Question

An object is projected upward with a velocity of 100 m/s.It will strike the ground in approximately a) 10s b)20s c)15s

Answer 1

If the object is projected vertically upward , then time period of motion is given by

: 2u/g
where 'u' is initial velocity of projectile.
i.e. T = 2* 100/10
= 20s


It will strike the ground at 20s.

Answer 2

The object will strike the ground at approximately 20s.