Question

A cart is moving with speed 20m/s on a horizontal track.A body is projected with speed of 40m/s(relative to cart)from the cart such that path of the body appear to be straight line for an observer on ground.Time for which body remains in air is

Answer 1

Explanation:

From the inertial frame this is a projectile motion with range 80m and horizontal velocity 30 m. Time of flight is 80/30=8/3 s. displacement along y direction is zero.

H=ut−

2

1

gt

2

=0

⇒u=

2

gt

=

2

10×

3

8

=

3

40

m/s