Question

From what height should a body of 40 kg fall in order to have same kinetic energy as a body of mass 1.96 kg travelling at 12 m/s solution

Answer 1

Let ' h ' height should a body of mass 40kg fall.

a/c to question,

potential energy of body of mass 40kg at h height = kinetic energy of body of mass 1.96kg moves with speed 12 m/s

or, Mgh = 1/2 mv²

or, 40 × 9.8 × h = 1/2 × 1.96 × 12²

or, 40 × 9.8 × h = 0.98 × 144

or, 400 × h = 144

or, h = 144/400 = 38/100 m = 0.38 m or 38cm

hence, answer is 38cm

Answer 2

Answer:

Let ' h ' height should a body of mass 40kg fall.

a/c to question,

potential energy of body of mass 40kg at h height = kinetic energy of body of mass 1.96kg moves with speed 12 m/s

or, Mgh = 1/2 mv²

or, 40 × 9.8 × h = 1/2 × 1.96 × 12²

or, 40 × 9.8 × h = 0.98 × 144

or, 400 × h = 144

or, h = 144/400 = 38/100 m = 0.38 m or 38cm

hence, answer is 38cm