A ball is thrown vertically upward with a velocity 20m/sec from a top of a building.the height of the point from where the ball is thrown is 25m from the grouund.how high will the ball raise from ground and how long will it take before the ball hits the ground
Answers
Answered by
1
(a) H = u²/(2g)
H = 20²/(2×10)
H = 20 m
The ball will reach 20 m high from the point of projection.
It reaches 20 + 20.5 = 40.5m high from the ground.
(b) t1 = 2u/g
t1 = 2×20/10
t1 = 4 seconds
If v is the velocity with which it hits the ground then,
v = √(u² + 2aS)
v = √(20² + 2×10×25)
v = 30 m/s
v = u + at
t2 = (v - u)/g
t2 = (30 - 20)/10
t2 = 1 second
Time taken for it to hit the ground = t1 + t2
= 4 + 1
= 5 seconds
H = 20²/(2×10)
H = 20 m
The ball will reach 20 m high from the point of projection.
It reaches 20 + 20.5 = 40.5m high from the ground.
(b) t1 = 2u/g
t1 = 2×20/10
t1 = 4 seconds
If v is the velocity with which it hits the ground then,
v = √(u² + 2aS)
v = √(20² + 2×10×25)
v = 30 m/s
v = u + at
t2 = (v - u)/g
t2 = (30 - 20)/10
t2 = 1 second
Time taken for it to hit the ground = t1 + t2
= 4 + 1
= 5 seconds
Similar questions