Question

John is lifting a 1.5 kg toy to a height of 1.2 m above the ground. How much work is done??

Answer 1

This question should have been asked in the physics sections but I'll still provide you an answer.

Work done (Joules) = Force (N) x Distance (m)
The only force that we know of that is acting on the toy (ignoring resistive forces) is the weight and tension of the string lifting the object. Weight = mass x acceleration due to gravity = mg. The tension is the force that is causing the work to be done and is equal to the weight. So tension = mg.

Work Done = Tension x distance.
= 1.5 x 9.8 x 1.2