Question

A ball of mass m is drop from a height of H. When it's position is H/3 calculate the ratio of potential energy and kinetic energy.
1. 1/4
2. 1/2
3. 1
4. 1/3

Answer 1

Dear Student,

● Answer -

(2) 1/2

◆ Explanation -

Potential energy of the ball is given by -

P.E. = mgh

P.E. = m × g × H/3

P.E. = mgH/3

Using Newton's kinematic equation,

v² = u² + 2as

v² = 0² + 2 × g × 2H/3

v² = 4gH/3

Kinetic energy of the ball is given by -

K.E. = ½mv²

K.E. = 1/2 × m × 4gH/3

K.E. = 2mgH/3

Ratio of P.E. to K.E. is given by -

PE/KE = (mgH/3) / (2mgH/3)

PE/KE = 1/2

Thanks for asking. Hope this is helpful...