# Homework Help: Mass sliding at an angle

1. Oct 6, 2016

### Kpgabriel

1. The problem statement, all variables and given/known data
M1 and M2 are two masses connected as shown.
https://loncapa2.physics.sc.edu/res/msu/physicslib/msuphysicslib/09_Force_and_Motion/graphics/prob75_fricpullplane.gif

The pulley is light and frictionless. Find the mass M1, given that M2 (3.50 kg) is moving downwards and accelerates downwards at 2.99 m/s2, that θ is 20.0°, and that μk is 0.470.

2. Relevant equations
F = ma

3. The attempt at a solution
So I have broken down the components of the forces especially for M1 because the Mg force has the components sin and cos. I found the force in the y direction of M1 to be Fn=M1gSin(theta). Then I found the x direction to be T(tension)-u(friction)Fn-M1gCos(theta)=M1a. Which would make T= M1(ugSin(theta) + gCos(theta) +a). And for block 2 I have T = M2(g-a). Then I set the T's equal to each other and solve for M1 but it seems to be wrong.

2. Oct 6, 2016

3. Oct 6, 2016

### Kpgabriel

Ok I think I got it

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4. Oct 6, 2016

### PeroK

Are you sure you haven't got $\cos$ and $\sin$ mixed up?

5. Oct 6, 2016

### Kpgabriel

I did.... Thank you so much!