Question

If an object is thrown straight up from the ground what velocity does it need to be thrown in order to reach a height of 50 ft?

Answer 1

40 ft/sec

Explanation:

height h = 50 ft

final velocity v would be zero.

acceleration a = -32 ft/sec^2

we kn that

u^2=v^2+2ah

u^2= 0^2- 32×50

u= √(32×50)

u= 40 ft/sec

the object must be thrown with the velocity of 40 ft/sec

Answer 2

Object is thrown with a velocity of 56.74 m/sec

Explanation:

We have given height h = 50 feet

When the object reach at its maximum height its final velocity will be o

So final velocity v = 0 m/sec

Acceleration due to gravity
`g=-32.2feet/sec^2` ( Negative sign is due to upward direction )

From third equation of motion

`v^2=u^2+2gh`

`0^2=u^2-2* 32.2* 50`

`u^2=3220`

`u=56.74m/sec`

So object is thrown with a velocity of 56.74 m/sec