# Brain cramp and need equation

1. Jan 31, 2008

### Melchior25

1. The problem statement, all variables and given/known data

Young David who slew Goliath experimented with slings before tackling the giant. He found that he could revolve a sling of length 0.750 m at the rate of 10.0 rev/s. If he increased the length to 1.050 m, he could revolve the sling only 8.00 times per second.

What is the speed of the stone for each rate of rotation?

a) .... m/s at 10.0 rev/s

b) .... m/s at 8.00 rev/s

3. The attempt at a solution

I can probably figure this out but I forgot my book and don't want to guess. Please could you tell me the equation that I use.

Thanks.

2. Jan 31, 2008

It is most likely the relationship between angular movement and tangential.
$$V_t=r \cdot\omega$$

Casey

3. Jan 31, 2008

### Melchior25

Thanks, I got it.

I just took the circumference and multiplied that by the rotations/sec.