Posted by **Joey** on Thursday, September 16, 2010 at 4:35pm.

Two balls are dropped, one from height H and the other from a height of 4H. How far apart should they be dropped (time wise) to hit the ground at the same time.

- physics -
**bobpursley**, Thursday, September 16, 2010 at 6:35pm
h=1/2 g t^2 is the basic formula.

H=1/2 g (t-to)^2 where to is the time the lower one is dropped, after the higher.

4H=1/2 g t^2

So, both balls hit at time t.

t=sqrt 8H/g

H=1/2 g (sqrt(8H/g)-to)^2

2H=g(8H/g-2to*sqrt(8H/g)+to^2)

so you have a quadratic...

to^2-2to* sqrt(8H/g)-2H/g

a=1 b=-2sqrt(8H/g) c= -2H/g

solve by the quadratic equation.

## Answer This Question

## Related Questions

- physics - two balls are dropped to the ground from different heights. one ball ...
- physics - How many secons apart should two balls be released so that a ball ...
- physics - A mass is dropped from a height of 30m, and at the same time from ...
- Physics - A mass is dropped from a height of 30m, and at the same time from ...
- PHYSICS - A BALL IS DROPPED A HEIGHT AT THE SAME TIME AS ANOTHER BALL IS ...
- Physics - Two balls are dropped from rest from the same height. One of the balls...
- physics - A mass is dropped from a height of 30m, and at the same time from ...
- science - A class is learning about acceleration due to gravity. Their plan is ...
- Math - A ball is dropped from a height of 36 feet. The quadratic equation d=1/2 ...
- physical science - A clam is dropped by a seagull it takes 3 seconds to hit the ...

More Related Questions