Posted by **Anonymous** on Saturday, March 15, 2008 at 7:42pm.

A ball is thrown from the top edge of a building with initial velocity components of 15m/s(up) vertically and 20m/s horizontally. It strikes ground 140m from the base of the building. What is the height of the building?

I tried using V2^2 = V1^2 + 2ad and it gave me 11.25 which I know is wrong. How would I calculate this?

- Physics -
**Quidditch**, Saturday, March 15, 2008 at 10:51pm
The ball lands 140m from the base of the building. The balls initial horizontal velocity is 20m/s.

140m = (20m/s) * t

Solve for t.

Since the time the ball is in flight is now known.

Plug that into the "complete" formula for distance:

d = (1/2)*(g)*(t^2) + v*t + h

Let distance 0 be ground level.

initial vertical velocity is v=15m/s

h is the initial distance above the ground which is the height of the building.

0 = (1/2)*(g)*(t^2) + v*t + h

Solve for h.

Remember that the initial velocity is up and the acceleration of gravity is down (watch the signs)

- Physics -
**~christina~**, Saturday, March 15, 2008 at 11:40pm
I helped you with this question yesterday and gave the exact same info as Quidditch Why didn't you use the info I gave?

## Answer This Question

## Related Questions

- Physics - A ball is thrown from the top edge of a building with initial velocity...
- Physics - A ball is thrown from the top edge of a building with initial velocity...
- Physics - A ball is thrown horizontally from the top of a building 45.2 m high. ...
- physics - a ball is thrown horizontally from the top of a building 35m. high. ...
- Physics - From the window of a building, a ball is tossed from a height y0 above...
- Physics - From the window of a building, a ball is tossed from a height y0 above...
- Physics - From the window of a building, a ball is tossed from a height y 0 ...
- physics - A ball is thrown horizontally with an initial velocity of 20.0 m/s ...
- Physics - A ball thrown horizontally from the top of a 13m high building ...
- Physics - An object is thrown from the top edge of a building at a speed of 21....

More Related Questions