# Homework Help: Circular motion related to linear motion

1. Oct 5, 2009

### songoku

1. The problem statement, all variables and given/known data
As block B moves upward with constant speed 2 m/s, pin A glides through the semicircular slot. At the position shown, determine the velocity of A.

a. 2.31, angle 60o
b. 2.00, angle 60o
c. 1.00, angle 0o
d. 1.89, angle 30o

2. Relevant equations
Not sure

3. The attempt at a solution
A and B will have the same speed, so the answer is b (the angle is 60o to the horizontal) ???

Thanks

2. Oct 5, 2009

### Vykan12

The velocity vector of A is going to be tangent to the circle, so its angle relative to the horizontal will be 60 degrees (you can check this with some simple geometry). We also know that the vertical compontent of this vector is 2 since it is given by object B. By pythagoras the magnitude of the vector must be greater than 2. Therefore, the answer must be (a).

3. Oct 5, 2009

### songoku

Hi Vykan12

Oh I get it. Thanks a lot Vykan12