Question

A student lifts an object in the upward direction. In doing so, he applies the force on the object in

the upward direction and displaces it in that direction: (However, the force of gravity is also

acting on the object.)

(a) State the direction in which force of gravity is acting on it.

(b) Which one of these forces is doing positive work? Give reason.

(c) Which one of these forces is doing negative work? Give reason.​

Answer 1

a) downwards

b) the force with which the student is applying because it is in the direction of movement

c) gravitational force , as it is opposite to the direction of movement

Answer 2

a) the gravity is acting in the downward direction.

b) The force exerted by the boy because he is applying force .

c)The force exerted by the gravity because as you everything that falls comes down and it is acting against the force applying by the boy.