Posted by **sara** on Sunday, September 17, 2006 at 2:44pm.

A stone is dropped into a river from a bridge 43.9 m above the water. Another stone is dropped vertically down 1s after the first is dropped. Both stones strike the water at the same time.

a) What is the initial speed of the second stone?

Write an equation for the vertical height of each stone. Let t=0 be the time the first stone is dropped. The second stone must have an initial vertical (downward) velocity so it can catch up with the first.

Y1 = 43.9 - (g/2) t^2

Y2 = 43.9 - Vo (t-1) - (g/2)(t-1)^2

Set Y1 = 0 and Y2 = 0 (the heights when each hit the ground). Use the first equation to solve for t. Use the second equation to solve for Vo, the initial downward velocity of the second stone. Note that t-1 is the time of flight of the second stone.

## Answer This Question

## Related Questions

- physics - A stone is dropped into a river from a bridge 43.8 m above the water. ...
- physics - A stone is dropped into a river from a bridge 45.4 m above the water. ...
- physics - A stone is dropped into a river from a bridge 45.4 m above the water. ...
- physics - A stone is dropped into a river from a bridge 45.4 m above the water. ...
- physics - A stone is dropped into a river from a bridge 43.3 m above the water. ...
- physics - A stone is dropped into a river from a bridge 41.7 m above the water. ...
- 12th grade Physics - A stone is dropped in water from a bridge 44 cm above the ...
- science - a stone is dropped down a well.it hits th surface of the water after ...
- Physics - A Stone Of Mass 1kg Is Dropped From Rest From A Window 20m Above The ...
- science - to find the height of a bridge over a river. a stone is dropped ...

More Related Questions