Question

A particle of mass 100g is thrown vertically upwards with a speed of 5m/s. The work done by the force of gravity during the time the particle goes up is

(a) 0.5J 

(b) –0.5J

(c) –1.25J 

(d) 1.25J.

Answer 1

(c) : Kinetic energy at projection point is converted into potential energy of the particle during rise. Potential energy measures the workdone against the force of gravity during rise.