Question

A 1 kg mass ball is moving on a horizontal surface with a velocity 20 m/s and reaches a plane which makes an angle of 30° with the horizontal. If friction is negligible then how much distance vertically will the ball reach?

Answer 1

M = 1kg; u = 20 m/s; θ = 30°

Therefore the retardation of the ball on the inclined plane,

If the ball moves for a distance S along the inclined plane before it stops, then using the relation.
v² = u² + 2as, we have,

Alternative method:

Total kinetic energy of a rolling body on the plane,

At the top of the inclined plane, the kinetic energy of the moving body is completely converted into the potential energy.
∴ U = E_t
or mgh = E_t
or 1 × 10 × h = 280
⇒ h = 28 m