posted by .

John Stands at the edge of a flat roof of a three story building and throws a 180g ball straight up into the air that reaches a height of 3.0 meters above the roof. ( building is 14 meters high)

A. What is the initial speed of the ball?
B. How long does it take to reach it's maximum height?
C. Assuming it misses the building on it's way down, at what speed does it hit the ground? ( building is 14 meters high)
D. What is the total length of the time the ball is in the air?
E. What is the intitial momentum of the ball?
F. What is the momentum of the ball at its peak?
G. What is the momentum of the ball when it hits the ground?

Thank you!

a. Vf^2 = Vi^2 + 2*a*d
solve for Vi given Vf = 0 (speed at max height is 0), a = -9.81 m/s^2 and d = 3m.

b. Once you know Vi, you can use
Vf = a*t + Vi and solve for t.
(once again, Vf = 0 since you're only considering the path of the ball from the top of the building to maximum height)

c. Vf^2 = Vi^2 + 2*a*d
(d = height of building + 3m)

d. Vf = a*t + Vi
Use your answer from part c. to solve for the time it takes the ball to fall from max height to the ground and then add your answer from part b. to get the total time.

e,f,g: momentum = m*v

## Similar Questions

1. ### Physics

A boy stands on the edge of a building 7 meters high and throws a rock at 60-degree angle. The release point from his hand is 1.6 meters above his feet(so the release point above the ground is 8.6 meters.) The rock lands on the ground …
2. ### physics

Frank stands at the base of a building. He throws a 0.12kg rock straight up at a speed of 28m/s so that it rises to a maximum height of 12m above the top of the building and then falls straight down on the roof of the building. a) …
3. ### Physics Gr.11

Frank stands at the base of a building. He throws a 0.12kg rock straight up at a speed of 28m/s so that it rises to a maximum height of 12m above the top of the building and then falls straight down on the roof of the building. a) …
4. ### physics

One side of the roof of a building slopes up at 35.5°. A student throws a Frisbee onto the roof. It strikes with a speed of 15.0 m/s and does not bounce, but slides straight up the incline. The coefficient of kinetic friction between …
5. ### physics

One side of the roof of a building slopes up at 30.5°. A roofer kicks a round, flat rock that has been thrown onto the roof by a neighborhood child. The rock slides straight up the incline with an initial speed of 15.0 m/s. The coefficient …
6. ### physics

One side of the roof of a building slopes up at 30.5°. A roofer kicks a round, flat rock that has been thrown onto the roof by a neighborhood child. The rock slides straight up the incline with an initial speed of 15.0 m/s. The coefficient …
7. ### physics

One side of the roof of a building slopes up at 30.5°. A roofer kicks a round, flat rock that has been thrown onto the roof by a neighborhood child. The rock slides straight up the incline with an initial speed of 15.0 m/s. The coefficient …
8. ### Physics

Carlos is in an roof of a building of 20 meters tall, he throws a tennis ball vertically upwards at 15 m/s velocity after it reaches its highest height, the ball goes down until it reaches the ground (see the figure). Based on this …
9. ### Physics

Carlos is in an roof of a building of 20 meters tall, he throws a tennis ball vertically upwards at 15 m/s velocity after it reaches its highest height, the ball goes down until it reaches the ground (see the figure). Based on this …
10. ### math

A girl stands on the edge of her dorm roof and throws a ball into the air. The​ ball's height above the ground after t seconds is given by h equals negative 16 t squared plus 64 t plus 80h=−16t2+64t+80. When will the ball …

More Similar Questions