# physics

posted by .

A student drops a ball from the top of a tall building; the ball takes 2.8 s to reach the ground.
1. what was the ball's speed just before hitting the ground?
2. What is the height of the building?

• physics -

assuming it drops from rest you know:
vo=0
t=2.8
a=9.8 (gravity assuming down is +)
v=?
use the equation v=vot+at^2

then you want to find height.
x= vot+.5at^2

• physics -

i love you sweat heart

• physics -

Fu

## Similar Questions

1. ### physics

A ball is thrown from the top of a building upward at an angle of 66 ◦ to the horizontal and with an initial speed of 16 m/s. The ball is thrown at a height of 53 m above the ground and hits the ground 33.2074 m from the base …
2. ### physics

A student drops a ball from the top of a tall building; the ball takes 2.4 to reach the ground. What was the ballâ€™s speed just before hitting the ground?
3. ### physics

A ball rolls along a desktop with an uniform velocity of 3 m/s. What is the displacement after 10 seconds have passed?
4. ### physics

A ball rolls along a desktop with an uniform velocity of 3 m/s. What is the displacement after 10 seconds have passed?
5. ### physics : HELP PLEASE

A ball rolls along a desktop with an uniform velocity of 3 m/s. What is the displacement after 10 seconds have passed?
6. ### physics : HELP PLEASE

A ball rolls along a desktop with an uniform velocity of 3 m/s. What is the displacement after 10 seconds have passed?
7. ### Physics

Ball A is thrown upward from the top of a building and takes 12 s to hit the ground. Ball B is thrown downward with the same speed as Ball A and takes 7 s to hit the ground. How long does it take for ball A to reach it peak?
8. ### Physics

A ball is thrown horizontally from the building roof at a speed of 20 m/s. Takes ball 4 seconds to reach the ground. How tall is building?
9. ### Maths

A circus artist drops a ball from a high wire. The ball takes 1.5 seconds to reach the ground. I) Find the height of the ball above the ground. II) How fast is the ball moving as it hits the ground?
10. ### Maths

A ball is thrown vertically upwards at 3 m s-1 from 1m above ground level (I) write down the equation for the height of the ball above the ground after t seconds (while the ball is in the air). (II) use your answer to find the time …

More Similar Questions