A stone is dropped into water from a bridge 44m above the water. Another stone is thrown vertically downward 1.0s after the first was dropped. Both stones strike the water at the same time. What was the initial velocity of the second stone?

Question

jamesj · Answer

So first calculate the time taken for the first stone to reach the water.

Then use that and the standard kinematic equations to find the initial velocity of the second stone.

anonymous · Answer

so for the first stone I have the displacement, acceleration due to gravity and would I say the initial velocity is 0m/s for the first stone?

jamesj · Answer

Yes. The stone travels 44m and takes time T then from
$$ s = v_0t + \frac{1}{2}at^2 $$
we must have that
$$ 44 = \frac{1}{2}gT^2 $$
Solve now for T.  

The second stone travels for time T-1. From that and using the same equation, you can find its initial velocity $ v_0 $.

anonymous · Answer

oh ok. Thanks