Physics 11 question?

Question

A 20 kg cart on wheels has been pushed up against a wall with a spring (k=244N/m) between the wall and cart. If the spring is compressed to a distance of 0.1m and a force of 20 N is continued to be applied toward the wall, what will the acceleration be?

Also, what kind of force is the 20N? Net force, applied force?

Answer 1

The force required to compress a spring is equal to distance*k, so here .1*244=24.4Newtons.

Let's assume that the spring will push outward towards the right, so we denote this as 24.4N.

But we push on this spring with a force of 20N to the left, so we denote that as -20N. This is also our applied force.

We want to know the Net force:

24.4N-20N=4.4N, to the right.

So a 4.4N force will be the net force exerted on the 20kg mass. To find acceleration, we use F=ma

So

4.4N=(20kg)*a
a=.22m/sec^2