Kinetic Energy Calculator
Calculate kinetic energy from mass and velocity with step-by-step explanations.
Kinetic Energy Formula
KE = ½mv²
where: m = mass (kg), v = velocity (m/s), KE = energy (joules)
Step-by-step: 1) Square velocity. 2) Multiply by mass. 3) Divide by 2.
Kinetic Energy Examples
| Object | Mass | Velocity | KE (approx) |
|---|---|---|---|
| Baseball | 0.145 kg | 40 m/s | 116 J |
| Person running | 70 kg | 5 m/s | 875 J |
| Car on highway | 1500 kg | 25 m/s | 469 kJ |
| Bullet | 0.01 kg | 400 m/s | 800 J |
Frequently Asked Questions
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Energy of motion. Any moving object has kinetic energy. KE = ½mv², where m = mass (kg), v = velocity (m/s). Measured in joules (J).
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Kinetic energy depends on velocity squared (v²). Doubling velocity quadruples kinetic energy (2² = 4). Velocity has more impact than mass.
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Energy is work needed to accelerate object from rest. Work = F·d, and d increases with v²/2a by kinematics. Results in KE ∝ v².
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KE is directly proportional to mass. Doubling mass doubles KE (at same velocity). But this effect is weaker than velocity effect.
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Yes. KE = ½mv² is always positive (mass and v² are positive). An object moving at any speed has positive kinetic energy.
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Work done on object = change in kinetic energy. W = ΔKE. Positive work increases KE. Negative work (friction) decreases KE.
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Kinetic: energy of motion (depends on velocity). Potential: energy of position (depends on height or spring compression). Both are mechanical energy.
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Yes. Friction converts KE to heat. Braking converts KE to heat/sound. Collision can convert KE to deformation. Total mechanical energy conserved.
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Moving car (depends on mass and speed—safety concern). Baseball pitch (why faster pitches are harder to catch). Wind turbines (converting wind KE to electricity).
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Impact energy calculations (vehicle crashes). Turbine design (extracting energy from flowing water/wind). Projectile motion analysis. Energy efficiency studies.
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SI unit: joule (J) = kg·m²/s². Also: erg, calorie, electron-volt, foot-pound. Always convert to joules for consistency.
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Identify m (kg) and v (m/s). Apply KE = ½mv². Be careful with units. For velocity changes, use KE_f - KE_i = work done.