Calculating Weight on Other Planets Formula

Calculate Weight on Other Planets | Gravity and Mass Explained :root { –primary-color: #004a99; –success-color: #28a745; –background-color: #f8f9fa; –text-color: #333; –secondary-text-color: #666; –border-color: #ddd; –shadow-color: rgba(0, 0, 0, 0.1); } body { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; line-height: 1.6; margin: 0; padding: 0; background-color: var(–background-color); color: var(–text-color); display: flex; flex-direction: column; align-items: center; } .container { width: 100%; max-width: 960px; margin: 20px auto; padding: 20px; background-color: #fff; border-radius: 8px; box-shadow: 0 4px 15px var(–shadow-color); display: flex; flex-direction: column; align-items: center; } header { width: 100%; background-color: var(–primary-color); color: white; padding: 20px 0; text-align: center; margin-bottom: 20px; border-radius: 8px 8px 0 0; } header h1 { margin: 0; font-size: 2.5em; } .calculator-section { width: 100%; padding: 30px; border-bottom: 1px solid var(–border-color); } .calculator-section:last-of-type { border-bottom: none; } .loan-calc-container { display: flex; flex-direction: column; align-items: center; gap: 20px; width: 100%; } .input-group { width: 100%; max-width: 450px; display: flex; flex-direction: column; gap: 8px; } .input-group label { font-weight: bold; color: var(–primary-color); } .input-group input[type="number"], .input-group select { padding: 12px 15px; border: 1px solid var(–border-color); border-radius: 5px; font-size: 1em; width: 100%; box-sizing: border-box; } .input-group input[type="number"]:focus, .input-group select:focus { outline: none; border-color: var(–primary-color); box-shadow: 0 0 0 3px rgba(0, 74, 153, 0.2); } .input-group .helper-text { font-size: 0.85em; color: var(–secondary-text-color); } .error-message { color: #dc3545; font-size: 0.85em; min-height: 1.1em; /* Reserve space for error message */ } .button-group { display: flex; flex-wrap: wrap; justify-content: center; gap: 15px; margin-top: 25px; } button { padding: 12px 25px; border: none; border-radius: 5px; font-size: 1em; font-weight: bold; cursor: pointer; transition: background-color 0.3s ease, transform 0.2s ease; } .primary-button { background-color: var(–primary-color); color: white; } .primary-button:hover { background-color: #003366; transform: translateY(-2px); } .secondary-button { background-color: var(–success-color); color: white; } .secondary-button:hover { background-color: #218838; transform: translateY(-2px); } .reset-button { background-color: #6c757d; color: white; } .reset-button:hover { background-color: #5a6268; transform: translateY(-2px); } .results-container { background-color: var(–primary-color); color: white; padding: 25px; border-radius: 8px; margin-top: 30px; width: 100%; box-sizing: border-box; text-align: center; box-shadow: 0 2px 10px rgba(0, 74, 153, 0.3); } .results-container h2 { margin-top: 0; font-size: 1.8em; color: white; } .main-result { font-size: 2.8em; font-weight: bold; margin: 15px 0; padding: 10px; background-color: rgba(255, 255, 255, 0.1); border-radius: 5px; display: inline-block; } .intermediate-results div { margin-bottom: 10px; font-size: 1.1em; } .intermediate-results span { font-weight: bold; color: rgba(255, 255, 255, 0.9); } .formula-explanation { font-size: 0.9em; color: rgba(255, 255, 255, 0.8); margin-top: 15px; border-top: 1px solid rgba(255, 255, 255, 0.2); padding-top: 15px; } table { width: 100%; border-collapse: collapse; margin-top: 30px; box-shadow: 0 2px 5px var(–shadow-color); } th, td { padding: 12px 15px; text-align: left; border: 1px solid var(–border-color); } thead { background-color: var(–primary-color); color: white; } tbody tr:nth-child(even) { background-color: #f2f2f2; } tbody tr:hover { background-color: #e9ecef; } caption { caption-side: bottom; font-style: italic; color: var(–secondary-text-color); margin-top: 10px; text-align: center; font-size: 0.9em; } canvas { display: block; margin: 30px auto; background-color: white; border-radius: 8px; box-shadow: 0 2px 10px var(–shadow-color); } .chart-legend { text-align: center; margin-top: 15px; font-size: 0.9em; color: var(–secondary-text-color); } .chart-legend span { display: inline-block; margin: 0 15px; } .chart-legend .color-box { display: inline-block; width: 15px; height: 15px; margin-right: 5px; vertical-align: middle; } .chart-legend .color-box.earth { background-color: var(–primary-color); } .chart-legend .color-box.other { background-color: var(–success-color); } .article-section { width: 100%; padding: 30px; margin-top: 30px; background-color: #fff; border-radius: 8px; box-shadow: 0 4px 15px var(–shadow-color); } .article-section h2, .article-section h3 { color: var(–primary-color); margin-bottom: 15px; } .article-section h2 { font-size: 2em; } .article-section h3 { font-size: 1.5em; } .article-section p, .article-section ul, .article-section ol { margin-bottom: 20px; } .article-section li { margin-bottom: 10px; } .article-section strong { color: var(–primary-color); } .faq-item { margin-bottom: 20px; padding: 15px; background-color: var(–background-color); border-left: 5px solid var(–primary-color); border-radius: 5px; } .faq-item h4 { margin: 0 0 8px 0; font-size: 1.2em; color: var(–primary-color); } #related-tools ul { list-style: none; padding: 0; } #related-tools li { margin-bottom: 15px; padding-bottom: 10px; border-bottom: 1px solid var(–border-color); } #related-tools li:last-child { border-bottom: none; } #related-tools a { color: var(–primary-color); font-weight: bold; text-decoration: none; } #related-tools a:hover { text-decoration: underline; } #related-tools p { font-size: 0.9em; color: var(–secondary-text-color); margin-top: 5px; } footer { text-align: center; padding: 20px; margin-top: 30px; width: 100%; color: var(–secondary-text-color); font-size: 0.9em; } /* Responsive adjustments */ @media (max-width: 768px) { header h1 { font-size: 1.8em; } .container { padding: 15px; } .calculator-section, .article-section { padding: 20px; } .main-result { font-size: 2em; } button { padding: 10px 20px; font-size: 0.95em; } th, td { padding: 10px; font-size: 0.9em; } }

Weight on Other Planets Calculator

Enter your weight in kilograms (kg).
Mercury Venus Earth Moon Mars Jupiter Saturn Uranus Neptune Pluto Choose a celestial body to see your weight.

Your Estimated Weight

–.– kg
Weight on Earth: 70.0 kg
Surface Gravity: 9.81 m/s² (Earth Standard)
Planet/Moon Gravity: –.– m/s²
Formula: Weight = Your Mass (kg) * Surface Gravity (m/s²)
Note: Your mass remains constant, only weight (force) changes due to gravity.
Earth Standard Gravity Selected Celestial Body Gravity
Comparison of Surface Gravities
Celestial Body Surface Gravity (m/s²) Your Weight (kg)
Mercury 3.70 –.–
Venus 8.87 –.–
Earth 9.81 –.–
Moon 1.62 –.–
Mars 3.71 –.–
Jupiter 24.79 –.–
Saturn 10.44 –.–
Uranus 8.69 –.–
Neptune 11.15 –.–
Pluto 0.62 –.–
Weight Comparison Across Solar System Bodies

Understanding Weight on Other Planets: A Comprehensive Guide

What is Weight on Other Planets?

The concept of "weight on other planets" refers to the force of gravity exerted by a celestial body on an object or person. It's a common point of fascination, often discussed in science fiction and astronomy. When we talk about your weight on the Moon or Mars, we're actually describing how strongly that body's gravity pulls on your constant mass. Your mass, which is the amount of matter in your body, doesn't change regardless of location. However, your weight, which is a force (mass times acceleration due to gravity), does change because the acceleration due to gravity varies significantly from one planet to another, and even between a planet and its moons. This difference in gravitational pull is a fundamental aspect of celestial mechanics and a key differentiator between planetary bodies. Understanding your weight on other planets helps us grasp the vast differences in gravitational forces across the solar system.

Who should use this calculator? Anyone curious about space, physics, or simply their own weight under different gravitational conditions. Students learning about gravity, amateur astronomers, science enthusiasts, and even educators looking for a visual aid will find this tool invaluable. It provides a tangible way to relate abstract scientific concepts to personal experience.

Common misconceptions include:

  • Mass changing: Many people mistakenly believe their mass changes on other planets. Mass is intrinsic to an object; weight is the force experienced.
  • Gravity being uniform: Assuming all planets have gravity similar to Earth's. The reality is a wide spectrum, from Mercury's weak pull to Jupiter's immense gravity.
  • Weightlessness meaning zero mass: In space, astronauts experience apparent weightlessness due to freefall, not because they have lost mass.

Weight on Other Planets Formula and Mathematical Explanation

Calculating your weight on another planet is straightforward once you understand the core principles. The fundamental formula relies on Newton's law of universal gravitation, but for practical purposes on a celestial body's surface, we simplify it using the concept of gravitational acceleration.

The weight (W) of an object is the force exerted on it by gravity. It is calculated as the product of the object's mass (m) and the acceleration due to gravity (g) at its location.

The Core Formula:

W = m * g

Where:

  • W represents Weight (the force).
  • m represents Mass (the amount of matter).
  • g represents the acceleration due to gravity at the surface of the celestial body.

Step-by-step derivation:

  1. Determine Your Mass: First, you need to know your mass. On Earth, we often state our weight in kilograms (kg), but technically, this is a measure of mass. To be precise, you'd find your mass in kilograms. If you know your weight in Newtons (N), you can find your mass by dividing your weight in Newtons by Earth's standard gravity (approximately 9.81 m/s²): Mass (kg) = Weight (N) / 9.81 m/s². However, for common usage, entering your "weight" in kg directly into the calculator is standard practice, as it implicitly represents your mass in kilograms.
  2. Find the Surface Gravity (g): Each planet and moon has a different surface gravity. This value is usually expressed in meters per second squared (m/s²). Earth's standard gravity is approximately 9.81 m/s². Other celestial bodies have significantly different values. For example, Mars has about 3.71 m/s², while Jupiter has about 24.79 m/s².
  3. Calculate Your Weight: Multiply your mass (from step 1) by the surface gravity of the planet or moon (from step 2). This gives you your weight on that specific celestial body. For example, if your mass is 70 kg and you are on Mars (g ≈ 3.71 m/s²), your weight on Mars would be 70 kg * 3.71 m/s² = 259.7 N. Our calculator displays this in kilograms for easier comparison, by dividing the force in Newtons by Earth's gravity (9.81 m/s²): (70 kg * 3.71 m/s²) / 9.81 m/s² = 26.48 kg (equivalent weight).

Variables Table:

Here's a breakdown of the key variables involved:

Variable Meaning Unit Typical Range (Solar System Surface)
Mass (m) The amount of matter in an object. It is an intrinsic property and does not change with location. Kilograms (kg) Constant for an individual (e.g., 50 kg to 150 kg for humans)
Surface Gravity (g) The acceleration experienced by an object due to the gravitational pull of a celestial body at its surface. Meters per second squared (m/s²) ~0.62 m/s² (Pluto) to ~24.79 m/s² (Jupiter)
Weight (W) The force exerted on an object by gravity. On Earth, often colloquially expressed in kg, which represents the force relative to Earth's gravity. Scientifically, it's a force measured in Newtons (N). Newtons (N) or Equivalent Kilograms (kg) Varies greatly depending on mass and g
Understanding the Variables for Weight Calculation

Practical Examples (Real-World Use Cases)

Understanding how weight changes is crucial for space exploration and provides fascinating insights into planetary physics. Let's look at some practical examples using our weight on other planets formula calculator:

Example 1: An Astronaut's Journey to Mars

Imagine an astronaut who weighs 80 kg on Earth. This means their mass is 80 kg, and Earth's gravity (9.81 m/s²) exerts a specific force on them. When this astronaut travels to Mars, their mass remains 80 kg, but Mars has a surface gravity of approximately 3.71 m/s².

  • Inputs:
    • Your Weight on Earth: 80 kg
    • Select a Planet/Moon: Mars
  • Calculation:
    • Weight on Mars = 80 kg * 3.71 m/s² (Mars gravity) / 9.81 m/s² (Earth gravity for equivalent kg display)
  • Outputs:
    • Your Estimated Weight on Mars: Approximately 30.4 kg
    • Surface Gravity: 3.71 m/s²
    • Planet/Moon Gravity: 3.71 m/s²

Interpretation: The astronaut would feel significantly lighter on Mars, weighing only about 30.4 kg in equivalent Earth-based kilograms. This lighter feeling has implications for mobility, equipment design, and physiological effects during long-duration stays.

Example 2: A Tourist on the Moon

Consider a person who weighs 65 kg on Earth. If they were to visit the Moon, they would experience a much weaker gravitational pull. The Moon's surface gravity is about 1.62 m/s².

  • Inputs:
    • Your Weight on Earth: 65 kg
    • Select a Planet/Moon: Moon
  • Calculation:
    • Weight on Moon = 65 kg * 1.62 m/s² (Moon gravity) / 9.81 m/s² (Earth gravity)
  • Outputs:
    • Your Estimated Weight on the Moon: Approximately 10.7 kg
    • Surface Gravity: 1.62 m/s²
    • Planet/Moon Gravity: 1.62 m/s²

Interpretation: On the Moon, this person would feel incredibly light, weighing just over 10 kg. This is why astronauts on the Moon appeared to bound and jump with ease – the reduced gravitational force makes movement feel effortless, though maintaining balance can be tricky.

How to Use This Weight on Other Planets Calculator

Using our interactive calculator to determine your weight on different celestial bodies is simple and intuitive. Follow these steps to get instant results:

  1. Enter Your Earth Weight: In the "Your Weight on Earth" field, input your current weight in kilograms (kg). This value represents your mass, which remains constant across the universe.
  2. Select a Celestial Body: Use the dropdown menu labeled "Select a Planet/Moon" to choose the location you're curious about (e.g., Mars, Jupiter, the Moon). The default is Earth.
  3. Calculate: Click the "Calculate Weight" button. The calculator will instantly process your input and display the results.

How to Read the Results:

  • Your Estimated Weight: This is the primary result, displayed prominently in kilograms. It shows how much you would "weigh" (the force of gravity on your mass) on the selected celestial body, expressed in a way that's comparable to your Earth weight.
  • Weight on Earth: Confirms the mass you entered.
  • Surface Gravity: Shows the gravitational acceleration (g) of the selected planet or moon in m/s².
  • Planet/Moon Gravity: Repeats the surface gravity for clarity.
  • Table and Chart: The table and chart provide a visual comparison of surface gravities and your calculated weight across various bodies in our solar system, offering context and broader understanding.

Decision-Making Guidance:

While this calculator is primarily for educational and curiosity purposes, the results can inform understanding for hypothetical scenarios. For instance, knowing that Jupiter's gravity is over twice Earth's (resulting in more than double your weight) highlights the challenges of building structures or launching vehicles from such a massive planet. Conversely, the Moon's low gravity explains the feasibility of lunar bases and the unique challenges (like bone density loss) astronauts face. Use the results to appreciate the diverse physical conditions across the solar system.

Key Factors That Affect Weight on Other Planets Results

While the core formula Weight = Mass × Gravity is simple, several factors underpin the 'g' value and thus influence the calculated weight:

  1. Mass of the Celestial Body: This is the most significant factor. More massive planets exert a stronger gravitational pull. Jupiter, being the most massive planet in our solar system, has the highest surface gravity.
  2. Radius of the Celestial Body: Gravity decreases with distance from the center of a mass. For bodies of similar mass, a smaller radius means the surface is closer to the center, resulting in stronger surface gravity. For example, Earth and Venus have similar masses, but Venus is slightly larger, leading to slightly less surface gravity.
  3. Composition and Density: While less direct than mass and radius, the internal density distribution can play a subtle role. However, for the major planets, mass and radius are the dominant factors determining surface gravity.
  4. Atmospheric Pressure (Indirect Effect): While atmospheric pressure itself doesn't directly change your *weight* (the gravitational force), it does contribute to what's often perceived as "resistance" or buoyancy effects, especially for gases. However, for solid objects like humans, the effect on measured weight is negligible compared to gravity. Our calculator focuses purely on gravitational force.
  5. Altitude Above Surface: The calculator provides surface gravity. As you move higher above a planet's surface, the gravitational pull weakens rapidly. So, your weight on Mount Everest would be slightly less than your weight at sea level on Earth, though the difference is minuscule for practical purposes.
  6. Gravitational Anomalies: On Earth, and potentially on other bodies, localized variations in density (e.g., massive ore deposits) can cause slight fluctuations in gravity across the surface. Our calculator uses average surface gravity values.

Frequently Asked Questions (FAQ)

Q1: Does my mass actually change when I go to another planet?

A: No, your mass (the amount of matter you are made of) remains the same regardless of your location in the universe. Only your weight, the force of gravity acting on your mass, changes.

Q2: Why does the calculator show my weight in kg for other planets? Isn't weight a force?

A: You are correct! Scientifically, weight is a force measured in Newtons (N). However, for convenience and easy comparison, this calculator displays your "weight" on other planets as an *equivalent* weight in kilograms. This is calculated by taking your Earth weight (in kg, representing your mass), multiplying it by the other planet's gravity, and then dividing by Earth's standard gravity (9.81 m/s²). This allows you to directly compare how heavy you would *feel* on different worlds relative to Earth.

Q3: Are the gravity values used in the calculator exact?

A: The calculator uses generally accepted average surface gravity values for major celestial bodies. These values can vary slightly based on different measurement sources and can fluctuate slightly across the surface of a planet due to density variations.

Q4: Can I use this calculator for moons other than Earth's Moon?

A: This calculator includes Earth's Moon. For other moons (like Jupiter's moons), specific surface gravity data can be complex to find and may not represent a single "surface" value due to their gaseous nature or irregular shapes. We've included the most commonly referenced bodies.

Q5: What is the difference between weight and mass?

A: Mass is a measure of the amount of matter in an object and is constant. Weight is the force of gravity acting on that mass. Think of it this way: you have the same amount of "stuff" (mass) whether you're on Earth or the Moon, but the Moon pulls on that "stuff" with less force, so you weigh less there.

Q6: Why is Jupiter's gravity so much higher than Earth's?

A: Jupiter is a gas giant and has vastly more mass than Earth. According to Newton's law of universal gravitation, the more massive an object, the stronger its gravitational pull. Jupiter's immense mass creates a significantly stronger gravitational field at its cloud tops (which we consider its "surface" for gravity calculations).

Q7: Does Pluto have gravity?

A: Yes, Pluto has gravity, although it is much weaker than Earth's. Because Pluto is much less massive and smaller than Earth, its surface gravity is only about 6% of Earth's. Our calculator includes Pluto for comparison.

Q8: How does this relate to space travel?

A: Understanding different gravitational forces is crucial for space travel. It affects rocket launch calculations (overcoming gravity), the design of spacecraft, the physiological effects on astronauts (muscle and bone loss in microgravity or low gravity), and the mechanics of landing on different bodies.

© 2023 Your Company Name. All rights reserved.

var planetGravities = { mercury: 3.70, venus: 8.87, earth: 9.81, moon: 1.62, mars: 3.71, jupiter: 24.79, saturn: 10.44, uranus: 8.69, neptune: 11.15, pluto: 0.62 }; var earthGravity = 9.81; // Standard Earth gravity in m/s² var chart; // Declare chart variable globally function calculateWeight() { var weightOnEarthInput = document.getElementById('weightOnEarth'); var planetSelect = document.getElementById('planet'); var weightOnEarthError = document.getElementById('weightOnEarthError'); var planetError = document.getElementById('planetError'); var weightOnEarth = parseFloat(weightOnEarthInput.value); var selectedPlanet = planetSelect.value; // Reset errors weightOnEarthError.textContent = "; planetError.textContent = "; var isValid = true; // — Input Validation — if (isNaN(weightOnEarth) || weightOnEarth <= 0) { weightOnEarthError.textContent = 'Please enter a valid weight (greater than 0).'; isValid = false; } // Update intermediate displays and table rows document.getElementById('weightOnEarthDisplay').textContent = 'Weight on Earth: ' + weightOnEarth.toFixed(1) + ' kg'; document.getElementById('surfaceGravityDisplay').textContent = 'Surface Gravity: ' + earthGravity.toFixed(2) + ' m/s² (Earth Standard)'; var planetGravity = planetGravities[selectedPlanet]; document.getElementById('planetGravityDisplay').textContent = 'Planet/Moon Gravity: ' + planetGravity.toFixed(2) + ' m/s²'; var mainResultElement = document.getElementById('mainResult'); var planetWeightEquivalentKg; if (isValid) { // — Calculation — // Weight on planet = (Mass * Planet Gravity) / Earth Gravity (to get equivalent kg) planetWeightEquivalentKg = (weightOnEarth * planetGravity) / earthGravity; mainResultElement.textContent = planetWeightEquivalentKg.toFixed(2) + ' kg'; // — Update Table — updateGravityTable(weightOnEarth); // — Update Chart — updateChart(planetWeightEquivalentKg, planetGravity, selectedPlanet); } else { mainResultElement.textContent = '–.– kg'; document.getElementById('planetGravityDisplay').textContent = 'Planet/Moon Gravity: –.– m/s²'; // Clear table and chart if invalid input var tableRows = document.getElementById('gravityTableBody').getElementsByTagName('tr'); for (var i = 0; i < tableRows.length; i++) { tableRows[i].cells[2].textContent = '–.–'; } if (chart) { chart.destroy(); // Destroy existing chart instance if it exists chart = null; // Set chart to null } } } function updateGravityTable(weightOnEarth) { var tableBody = document.getElementById('gravityTableBody'); var rows = tableBody.getElementsByTagName('tr'); for (var i = 0; i < rows.length; i++) { var cells = rows[i].cells; var planetName = rows[i].cells[0].textContent.toLowerCase().replace(' ', ''); // Remove space for lookup // Handle Pluto specifically as it's often treated differently if (planetName === 'pluto') { planetName = 'pluto'; // Ensure correct key } else if (planetName === 'earth') { cells[2].textContent = weightOnEarth.toFixed(2); // Your weight on Earth continue; } var gravity = planetGravities[planetName]; var equivalentWeight = (weightOnEarth * gravity) / earthGravity; cells[2].textContent = equivalentWeight.toFixed(2); } } function updateChart(selectedPlanetWeight, selectedPlanetGravity, selectedPlanetKey) { var ctx = document.getElementById('gravityChart').getContext('2d'); // Destroy previous chart if it exists if (window.chartInstance) { window.chartInstance.destroy(); } var earthWeightEquivalent = parseFloat(document.getElementById('weightOnEarth').value); if (isNaN(earthWeightEquivalent) || earthWeightEquivalent <= 0) earthWeightEquivalent = 70; // Default if input is bad var otherPlanetData = { label: 'Selected Body Gravity', data: [selectedPlanetGravity], backgroundColor: 'rgba(40, 167, 69, 0.6)', // Green for selected borderColor: 'rgba(40, 167, 69, 1)', borderWidth: 1 }; var earthData = { label: 'Earth Gravity', data: [earthGravity], backgroundColor: 'rgba(0, 74, 153, 0.6)', // Blue for Earth borderColor: 'rgba(0, 74, 153, 1)', borderWidth: 1 }; var chartData = { labels: [selectedPlanetKey.charAt(0).toUpperCase() + selectedPlanetKey.slice(1)], // Capitalize planet name datasets: [earthData, otherPlanetData] }; window.chartInstance = new Chart(ctx, { type: 'bar', data: chartData, options: { responsive: true, maintainAspectRatio: false, scales: { y: { beginAtZero: true, title: { display: true, text: 'Gravity (m/s²)' } }, x: { title: { display: true, text: 'Celestial Body' } } }, plugins: { legend: { display: false // Hide default legend, use custom one }, title: { display: true, text: 'Gravity Comparison: Earth vs. ' + selectedPlanetKey.charAt(0).toUpperCase() + selectedPlanetKey.slice(1) } } } }); } function resetCalculator() { document.getElementById('weightOnEarth').value = 70; document.getElementById('planet').value = 'earth'; document.getElementById('weightOnEarthError').textContent = ''; document.getElementById('planetError').textContent = ''; // Reset intermediate results and main result document.getElementById('weightOnEarthDisplay').textContent = 'Weight on Earth: 70.0 kg'; document.getElementById('surfaceGravityDisplay').textContent = 'Surface Gravity: 9.81 m/s² (Earth Standard)'; document.getElementById('planetGravityDisplay').textContent = 'Planet/Moon Gravity: 9.81 m/s²'; document.getElementById('mainResult').textContent = '70.00 kg'; // Reset to Earth weight equivalent // Reset table var tableRows = document.getElementById('gravityTableBody').getElementsByTagName('tr'); for (var i = 0; i < tableRows.length; i++) { var cells = tableRows[i].cells; var planetName = cells[0].textContent.toLowerCase().replace(' ', ''); if(planetName === 'earth') { cells[2].textContent = '70.00'; } else { cells[2].textContent = '–.–'; } } // Reset chart if (window.chartInstance) { window.chartInstance.destroy(); window.chartInstance = null; } // Re-initialize a basic chart or clear canvas var ctx = document.getElementById('gravityChart').getContext('2d'); ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height); // Clear canvas content // Need to re-add initial chart state if desired, or just clear it. // For simplicity, let's just clear it. If a default chart is needed, // call updateChart with default values. updateChart(70, 9.81, 'earth'); // Re-initialize with Earth values } function copyResults() { var mainResult = document.getElementById('mainResult').textContent; var weightOnEarthDisplay = document.getElementById('weightOnEarthDisplay').textContent; var surfaceGravityDisplay = document.getElementById('surfaceGravityDisplay').textContent; var planetGravityDisplay = document.getElementById('planetGravityDisplay').textContent; var selectedPlanet = document.getElementById('planet').options[document.getElementById('planet').selectedIndex].text; var assumptions = "Key Assumptions:\n"; assumptions += "- Your mass remains constant.\n"; assumptions += "- Using average surface gravity values.\n"; assumptions += "- 'Weight' displayed in equivalent kg for comparison.\n"; var resultsText = "Weight on Other Planets Results:\n"; resultsText += "———————————-\n"; resultsText += mainResult + " on " + selectedPlanet + "\n"; resultsText += weightOnEarthDisplay + "\n"; resultsText += surfaceGravityDisplay + "\n"; resultsText += planetGravityDisplay + "\n"; resultsText += "———————————-\n"; resultsText += assumptions; // Use a temporary textarea to copy text var textArea = document.createElement("textarea"); textArea.value = resultsText; textArea.style.position = "fixed"; textArea.style.left = "-9999px"; document.body.appendChild(textArea); textArea.focus(); textArea.select(); try { var successful = document.execCommand('copy'); var msg = successful ? 'Results copied successfully!' : 'Failed to copy results.'; alert(msg); // Simple feedback } catch (err) { alert('Oops, unable to copy. Please copy manually.'); } document.body.removeChild(textArea); } // Initialize calculator on page load document.addEventListener('DOMContentLoaded', function() { // Initial calculation on load calculateWeight(); // Initial chart setup updateChart(70, 9.81, 'earth'); // Default to Earth }); // — Chart.js Initialization (assuming Chart.js library is available) — // Note: For a purely self-contained HTML file without external JS, // you would need to implement a canvas drawing logic manually or // use SVG, which is more complex. For this example, we'll assume // Chart.js can be loaded or is provided globally. // If Chart.js is NOT available, this part needs a complete rewrite using native canvas API. // Basic Chart.js fallback/placeholder if not available // THIS IS A PLACEHOLDER AND REQUIRES Chart.js LIBRARY TO FUNCTION // If Chart.js is not included via CDN, this WILL NOT WORK. // For a production-ready, self-contained solution, replace this with pure SVG or Canvas API. if (typeof Chart === 'undefined') { console.warn("Chart.js library not found. Charts will not be rendered."); // Optionally, disable chart canvas or show a message var canvas = document.getElementById('gravityChart'); var ctx = canvas.getContext('2d'); ctx.fillStyle = "#eee"; ctx.fillRect(0, 0, canvas.width, canvas.height); ctx.fillStyle = "#333"; ctx.font = "16px Arial"; ctx.textAlign = "center"; ctx.fillText("Chart library not available.", canvas.width/2, canvas.height/2); }

Leave a Comment