Question

how much energy is gained by a box of mass 20kg when man

(a)carrying wait for 5 minutes for a bus?

(b) run carrying the box with a speed of 3m/s to catch the bus?

(c)raise the box by 0.5 in order to place it inside the bus?

Answer 1

1. zero because it is at rest
2.1/2 ×20 ×3×3
=90j
3 mgh =20×10×0.5
=100,j
I hope it will help you

Answer 2

a) no energy gained.
b)no energy gained as muscular energy is converted into kinetic energy.
c) potential energy gained= mgh
= 20 * .5 * 10 joules
= 100 J