Question

A man of mass 50 kg is standing in an elevator. If elevator is moving up with an acceleration then work
done by normal reaction of floor of elevator on man when elevator moves by a distance 12 m is
(g = 10 m/s2)
​

Answer 1

Answer:

8000J

Explanation:

The work done on the man by the floor will equal his change in potential energy plus his change in kinetic energy.

If we assume the elevator starts at rest, the velocity at the distance of 12 m can be found using the kinematic equation

v² = v₀² + 2ad

v² = 0² + 2(10/3)12

v² = 80

U = ΔPE + ΔKE

U = mgh + ½mv²

U = m(gh + ½v²)

U = 50(10(12) + ½80)

U = 8000 J

Answer 2

Hope this help you☺️