Question

A ball is dropped from rest from a tower and strikes the ground 110 m below. Approximately, how many seconds does it take the ball to strike the ground after being dropped? Neglect air resistance.

A) 2.50 s

B) 3.50 s

C) 4.74 s

D) 12.5 s

E) 16.0 s

Answer 1

Time taken by ball to reach the ground will be equal to 4.74 second

So option (C) will be correct answer

Step-by-step explanation:

It is given that ball is dropped from rest so initial velocity of ball u = 0 m/sec

Height from which the ball is dropped h = 110 m

Acceleration due to gravity
`g=9.8m/sec^2`

From second equation of motion we know that
`s=ut+(1)/(2)gt^2`

So
`110=0* t+(1)/(2)* 9.8* t^2`

`t^2=22.448`

t = 4.74 second

So time taken by ball to reach the ground will be equal to 4.74 second

So option (C) will be correct answer