# Sled on an snow covered hill

## Homework Statement

A rope attached to a 18.0kg wood sled pulls the sled up a 22.0 degree snow-covered hill. A 9.00kg wood box rides on top of the sled.

Mass of Sled: 18kg
Mass of Box: 9kg
Angle of Incline: 22 Deg

If the tension in the rope steadily increases, at what value of the tension does the box slip?

F=ma

## The Attempt at a Solution

So I tried getting the overall tension that keeps the sled and box in equilibrium. So the tension is equal to the weight component down the slope which would be (27)(9.8)(sin 22). That gives that the tension is ~99N. So anything over that would make it slip but nope... apparently it's wrong.

## The Attempt at a Solution

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Doc Al
Mentor
Consider the friction between box and sled. (Looks like information is missing from your problem statement.)

The friction is not given in the problem.

Doc Al
Mentor
The friction is not given in the problem.
If there's no friction between box and sled, the box will slide. Does your book give a coefficient of friction for wood on wood?

you need the coefficient of friction between box and sledge and then work with fbd of box and sled