# A 20.0kg sled is being pulled across a horizontal surface at a CONSTANT VELOCITY.

1. Jul 29, 2009

### jandominic145

A 20.0kg sled is being pulled across a horizontal surface at a CONSTANT VELOCITY. The pulling force has a magnitude of 80.0 Newtons(N) and is directed at an angle of 30 degreesabove the horizontal. What is the coefficient of kinetic friction?

2. Jul 29, 2009

### Hootenanny

Staff Emeritus
Welcome to Physics Forums.

What are your thought's thus far? What have you attempted? The homework template is there for a reason, please use it.

3. Jul 29, 2009

### HallsofIvy

Staff Emeritus
What have you done on this? Have you determined the horizontal and vertical components of that pulling force?

4. Jul 29, 2009

### jandominic145

i want to know the formula and given
but i didn't understand this question

5. Jul 29, 2009

### Hootenanny

Staff Emeritus
What don't you understand about the question?

Please stop reporting posts. Try reply to a specific post, please us the quote button, or the reply box and the bottom of the page.

6. Jul 29, 2009

### Staff: Mentor

Hints:
(1) What forces act on the sled? Find the vertical and horizontal components.
(2) How does the friction force relate to the normal force?
(3) What does "constant velocity" tell you about the net force on the sled?

If these questions do not ring any bells or make no sense to you, then you are not ready to attack this problem. Crack open the textbook or your class notes.

7. Jul 29, 2009

### Hootenanny

Staff Emeritus
Simply repeating the question isn't going to get you anywhere. If you want our help, your going to have to start doing some work.

8. Jul 29, 2009

tnx Doc Al