# Acceleration across a frictionless surface

1. Oct 16, 2011

### Sammy101

Hi, I am confused on the topic of friction. I thought of a question that I cannot answer.

What happens if you push an object with a certain amount of force and mass on a frictionless surface? According to F=ma, you will be able to get the acceleration of the object, but how will you know when the object stops acceleration? Will the object accelerate infinitely?

2. Oct 16, 2011

### Drakkith

Staff Emeritus
As soon as you stop applying force to the object it will cease accelerating. IE if you push a block, as soon as you take your hand off or stop pushing it will cease accelerating.

3. Oct 16, 2011

### Sammy101

And so then it will just continue at a constant velocity right?

So, if you pushed on a 100kg object with 200N of force for 2s and then let go on a frictionless surface, the objects final velocity would be 4m/s because:

F=ma
200N=100kg(a)
a=2m/s^2

t=2s
velocity= 2m/s^2(2s) = 4m/s and thats how fast it would travel forever on a frictionless surface?

4. Oct 16, 2011

### Drakkith

Staff Emeritus
Yes, as soon as the force applied ceases, the object will continue at whatever velocity it was when you removed the force.

5. Oct 16, 2011

### Sammy101

Thank you!

6. Oct 16, 2011

### hemetite

Newton's first law & 2nd law