Kinetic Energy Calculator
Energy (Joules)
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Kilojoules
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Calories
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kWh
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Understanding Kinetic Energy
KE = (1/2)*m*v^2. Depends on mass and velocity squared. Doubling speed quadruples KE.
A 1500 kg car at 60 mph (26.8 m/s) has ~539 kJ. At 120 mph: ~2155 kJ (4x more). Why crashes are worse at speed.
Work-energy theorem: net work = change in KE = F*d*cos(theta).
Frequently Asked Questions
KE formula?
KE = (1/2)*m*v^2. Mass in kg, velocity in m/s, result in joules.
Why velocity matters more?
Velocity is squared. Doubling mass doubles KE; doubling velocity quadruples it.
KE of a bowling ball?
7 kg at 8 m/s: KE = 0.5*7*64 = 224 J. A baseball (0.145 kg) at 40 m/s: 116 J.
KE and stopping distance?
Stopping distance = KE / braking force. Since KE proportional to v^2, doubling speed quadruples stopping distance.