# Simple Forces

1. Oct 31, 2004

A box weighs 2000N and is accelerated uniformly over a horizontal surface at a rate of 8 m/s^2. The opposing force of friction between the box and the surface is 27.4 ..

How much force would be required to lift the box upward with an acceleration of 8 m/s^2?

I know that the answer is 3,630N .. but I'm not sure how to get there?

2. Oct 31, 2004

### Sirus

Some of the information in the question doesn't relate to the problem, but anyways, this is an application of $F_{net}=ma$. You know mass and acceleration, now what is the net force acting on the object while it is moved upward? Develop the equation and solve for applied force.

3. Oct 31, 2004

### Staff: Mentor

What forces act on the box when you lift it? Set the net force equal to ma (Newton's 2nd law).

4. Oct 31, 2004