A 2-kg box is lifted 1 m from the floor to a table top and then to a shelf 1 m above the table.?

Question

what is the gravitational potential energy the box gains

at the table top

on the shelf?

take g=10 N kg -1.

Answer 1

Gain of P.E. at the top of the table

= 2*10*1 = 20 J.

Gain of P.E. on the shelf with respect to the floor

= 2*10*2 = 40 J.