How Much Force Must the Man Exert to Move the Box?

[Ryo124]

Homework Statement

A man pushes a heavy box. The mass of the box is 100kg. There is friction between the man and the floor; the frictional force is 150N. As the mas pushes hard, the box accelerates with acceleration 0.3m/s/s. Calculate the force F exerted by the man on the box.

Homework Equations

F = ma

The Attempt at a Solution

Does the man need to at least exert 150N to overcome the force of friction? I don't know how to attempt the problem.

 

[Doc Al]

Does the man need to at least exert 150N to overcome the force of friction?

Absolutely. If you drew a diagram of the situation (always a good idea), what horizontal forces would you show acting on the box? Apply Newton's 2nd law to the box.

 

[Ryo124]

So the answer would be 180N, correct?

 

[Doc Al]

Correct.