Posted by **Koby** on Monday, September 20, 2010 at 12:38pm.

Ball is thrown horizontally off a cliff with an initial speed of 20m/s. a) how long does it take the ball to hit the ground 20m below. b)how long would it take to hit the ground if it was dropped from the cliff? c) how long would it take to hit the ground if it was thrown with an intial velocity of 20m/s at 18 degrees below the horizontal?

Not for sure if im doing this right.

For a) I used: change in x=vi*t; t=20m/20m/s

a) 1sec?

b) change in y=vi(of y) *t-1/2(g)(t^2)

20m=0*t-1/2(9.8)(t^2)

20m=4.9t^2

t^2=4.08

t=2.02 seconds

c) got 1.05 seconds, but that doesnt seem right to me, considering my answer for a)

Any help would be appreciated, especially if you can tell me where I'm going wrong.

## Answer this Question

## Related Questions

physics - A ball is thrown horizontally off the edge of a cliff with an initial ...

physics - a ball is dropped off a 20m high building, the ball weights 5 g. how ...

Physics for life scince - II.You are standing on the edge of a 50m high cliff ...

physics - A woman throws a ball at a vertical wall 40m away the ball is 20m ...

physics - A ball is thrown off a 30 m high cliff at 2 m/s, 50 degrees above the ...

physics - A ball is thrown horizontally at 10.0 m/s from the top of a hill 50.0 ...

college physics - a tennis ball is thrown straight up with an initial velocity ...

Physics - A ball thrown horizontally from an apartment balcony hits the ground ...

Physics please help!!!!!!! - A ball is thrown vertically upward (assumed to be ...

physics - A ball is thrown vertically upward with a speed of 23.7 m/s from a ...