Question

Two spheres of same size, one of mass $2\, kg$ and another of mass $4 \,kg$, are dropped simultaneously from the top of Qutab Minar (height $=72\, m$ ). When they are $1 \,m$ above the ground, the two spheres have the same :

• A. momentum
• B. kinetic energy
• C. potential energy
• D. acceleration

Answer 1

Answer: (D)

acceleration

Answer 2

When two spheres are dropped from rest, force of attraction due to earth acts on it. Under the force of attraction they will acquire the same acceleration which is due to gravitational effect. Also $g=\frac{GM}{R^2}$ in which acceleration due to gravity is independent of mass of the body. Hence, the two spheres have the same acceleration