Question

Which of the following statements accurately describes the sign of the work done on the box by the force of the push?

1- positive

2- negative

3- zore

Answer 1

Answer: positive

Explanation: according to newton's second law of motion, the applied force (pull) will produce a motion for the box defined by the formulae

f = ma, where m is the mass of the box and a is the acceleration.

But due to friction, a force of the same magnitude but opposite in direction to the push is applied, hence we have that

f - fr = ma

Where fr is the frictional force.

As we can see from the formulae, f (push) is responsible for a positive work while fr (friction) will bring about a negative work done.