# Can someone check if this forces problem on an incline

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1. Apr 4, 2016

To me the force P that pulls the bottom block up the incline seems a little low. Can someone confirm with my setup and work in brown is correct? Thank you.

Problem:

Work:

2. Apr 4, 2016

### BvU

Would you expect P to be independent of $\theta$ ?
Draw a free body diagram for each of the blocks separately.
And I see one of the two blue arrows (the most illegible one ) can't be right.

3. Apr 4, 2016

ΣFxA : P - T - (3mgsinθ) - μk mgcosθ= 0

That was your hint right XD.

4. Apr 4, 2016

### SammyS

Staff Emeritus
How about clearly stating what forces act on the plank and what forces act on the block - separately.

The mass of the block is 2m, right. Why do you have 3m ?

The plank acts on the block via friction and via the tension in the cord.

5. Apr 4, 2016