Physics (AS & A Level) · May / June 2022 · Paper 12 · Question 18

A student attempts to derive the formula for kinetic energy $E_K$. She begins by considering an object of mass $m$ which is initially at rest. A constant force $F$ applied to the object causes it to accelerate to final velocity $v$ in displacement $s$. The kinetic energy gained by the object is equal to the work done on the object by the force $F$. Which equation would the student not need in order to derive the formula for $E_K$?

1. A$F = ma$
2. B$W = Fs$
3. C$E = \frac{1}{2}Fs$
4. D$v^2 = u^2 + 2as$

As printed in the paper