# Homework Help: Inclined Planes

1. Sep 24, 2007

### polymerase

In this problem, the fact that the length of the string does not change imposes a constraint on relative accelerations of the two blocks. Find a relationship between the x component of the acceleration of block 2, $$a_{2x}$$,and the acceleration of block 1. Pay careful attention to signs.

Express $$a_{2x}$$ in terms of $$a_{1x}$$ and/or $$a_{1y}$$, the components of the acceleration vector of block 1.

(the diagram is included)

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2. Sep 24, 2007

### Staff: Mentor

Hint: How must the total accelerations of each block be related?

3. Sep 24, 2007

### polymerase

Equal?

4. Sep 24, 2007

### Staff: Mentor

Exactly!

5. Sep 24, 2007

### polymerase

so.....a_2x = a_1y?

6. Sep 24, 2007

### Staff: Mentor

Nope. Block 2 is on an incline. The magnitude of its total acceleration equals that of the other block, but they travel in different directions (obviously).

(I assume that x & y are horizontal and vertical. If x means parallel to the plane, then you are almost correct.)

7. Sep 24, 2007

### polymerase

....therefore FINAL answer is....a_2x = -a_y1??

8. Sep 24, 2007

### Staff: Mentor

If the x-axis is parallel to the incline for mass 2 and the y-axis is vertical for mass 2: Yes!

9. Sep 24, 2007

### polymerase

Yah...thanks for ur help