Q.
A car starts from rest and accelerates at 5m/s2 At t=4s, a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at t=6s ?
(Take g=10m/s2)
Velocity of the car at t=4sec is Vx=at=4×5=20m/s
So horizontal velocity =20m/s (remain constant)
Vertical velocity at t=6sec
i.e. after 2sec of free fall Vy=gt=20m/s
So net velocity =202+202=202m/s
and once it starts falling acceleration is only ' g '
i.e., 10m/s2