Kinetic energy when speed doubles
A cyclist doubles her speed. By what factor does her kinetic energy change?
Answer C: explanation for every choice
A
This would require increasing speed by only about 19%.
B
This treats kinetic energy as proportional to speed.
C
Correct. KE = ½mv², so doubling v multiplies KE by 2² = 4.
D
This treats kinetic energy as proportional to v³.
TakeawayKE ∝ v².
Equation usedKinetic and gravitational potential energy
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