# physics

posted by .

A ball is thrown vertically upward with an initial speed of 20 m/s. Two seconds later, a stone is thrown vertically (from the same initial height as the ball) with an initial speed of 24 m/s. At what height above the release point will the ball and stone pass each other?

• physics -

time that ball is in the air = t
time that stone is in the air =(t-2)
distance ball goes up = 20 t - 4.9 t^2
distance stone goes up = 24(t-2)-4.9 (t-2)^2
so
20 t -4.9 t^2 = 24 t - 48 - 4.9(t^2 - 4 t + 4)
20 t - 4.9 t^2 = 24 t - 48 - 4.9 t^2 + 19.6 t - 19.6
use t in distance equation for either ball or stone to get height

## Similar Questions

1. ### physics

A blue ball is thrown upward with an initial speed of 20.6 m/s, from a height of 0.8 meters above the ground. 2.5 seconds after the blue ball is thrown, a red ball is thrown down with an initial speed of 8.2 m/s from a height of 23.7 …
2. ### college

A blue ball is thrown upward with an initial speed of 19.8 m/s, from a height of 0.5 meters above the ground. 2.4 seconds after the blue ball is thrown, a red ball is thrown down with an initial speed of 7.9 m/s from a height of 22.5 …
3. ### physics

A red ball is thrown down with an initial speed of 1.2 m/s from a height of 25.0 meters above the ground. Then, 0.6 seconds after the red ball is thrown, a blue ball is thrown upward with an initial speed of 22.9 m/s, from a height …
4. ### Physics

A red ball is thrown down with an initial speed of 1.3 m/s from a height of 28.0 meters above the ground. Then, 0.6 seconds after the red ball is thrown, a blue ball is thrown upward with an initial speed of 24.7 m/s, from a height …
5. ### physics

ll is thrown vertically upward with an initial speed of 16 m/s. Then, 0.65 s later, a stone is thrown straight up (from the same initial height as the ball) with an initial speed of 27 m/s. How far above the release point will the …
6. ### physics

ll is thrown vertically upward with an initial speed of 16 m/s. Then, 0.65 s later, a stone is thrown straight up (from the same initial height as the ball) with an initial speed of 27 m/s. How far above the release point will the …
7. ### Physics

A red ball is thrown down with an initial speed of 1 m/s from a height of 27 meters above the ground. Then, 0.6 seconds after the red ball is thrown, a blue ball is thrown upward with an initial speed of 24.5 m/s, from a height of …
8. ### Physics

A ball is thrown vertically upward with an initial speed of 11 m/s . Then, 0.67 s later, a stone is thrown straight up (from the same initial height as the ball) with an initial speed of 25 m/s . How far above the release point will …
9. ### physics

A ball is thrown vertically upward with an initial speed of 25 m/s. Then, 1.8 s later, a stone is thrown straight up (from the same initial height as the ball) with an initial speed of 32.1 m/s . How far above the release point will …
10. ### Physics

A child throws a small ball vertically upwards. The ball is caught at the initial height 1.8 seconds after being thrown. What was the net displacement for the ball?

More Similar Questions