Ball from a cliff

  • Thread starter Stroodle
  • Start date
  • #1
26
0
A girl at the bottom of a [tex]100\ m[/tex] high cliff throws a tennis ball vertically upwards. A boy at the very top of the cliff drops a golf ball so that it hits the tennis ball while both balls are still in the air. The acceleration of both balls can be assumed to be [tex]10ms^{-2}[/tex] downwards.

With what speed is the tennis ball thrown so that the golf ball strikes it at the top of its path?

I don't know where to start with this one. Is the question missing something? I assume that both balls were both released at the same time...

Any help would be great.

Thanks
 

Answers and Replies

  • #2
61
0
for the tennis ball: v = vi + at
0 = vi -10t
(1) write an equation with t = ....

for the golf ball: d=vi x t + (at^2)/2
vi = 0 (for the golf ball) a = 10 and substitute the t from equation (1)

you'll end up with (2) d = ....

for the tennis ball: 100 - d = vi x t + (at^2)/2
a = -10, substite equation (2) for d, and substitute (1) for t

gudluck and tell me waht the answer is
 

Related Threads on Ball from a cliff

  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
1
Views
8K
  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
3
Views
6K
Replies
2
Views
3K
Replies
4
Views
4K
Replies
5
Views
2K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
3
Views
2K
Replies
2
Views
1K
Top