Question

A and B are two bodies each with mass A kg and B kg. Initially the bodies are at rest. Equal forces are exerted to A and B for the same duration. The ratio between the final kinetic energy of A and B is :

A. 1
B. B/A
C. A/B
D. (B/A)^2
E. (A/B)^2

Answer 1

kinetic energy of a particle with mass m and velocity v is
\[K_E=\frac{ 1 }{ 2 }mv^2\]
so
kinetic energy is directly proportional to the mass of the particle
\[(K_E)_A/(K_E)B=\frac{ M_A }{M_B }=A/B\]

Answer 2

thanks genuis !

Answer 3

no prob :)