Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
MHT CET202020 Oct 2020Morning ShiftPhysicsCenter of Mass, Momentum and CollisionActual

A ball kept at 20 ~m height falls freely in downward direction vertically and hits the ground. The coefficient of restitution is 0.4 . After the first rebound the upward velocity is [ g =10 ~m / s ² ]

Options

  1. A8 ~m / s
  2. B12 ~m / s
  3. C4 ~m / s
  4. D16 ~m / s

Correct answer

A. 8 ~m / s

Step-by-step solution

8 ~m / s h=20 ~m , e =0.4 ~m v²=0+2 g h=2 10 20 v=2 10=20e= u v u = ev =0.4 20=8 ~m / s

Practice Center of Mass, Momentum and Collision on Quantrex Academy →

More from Center of Mass, Momentum and Collision

A machine gun fires a bullet of mass m with a velocity of 1000 m/min. The man holding the gun can exert a force of 200 N on the gun. The product of mass of each bullet and the numb 2026Two bodies with kinetic energies in the ratio of 3:1 are moving with equal linear momentum. The ratio of their masses is 2026A body falls freely on to a hard horizontal surface. If the coefficient of restitution between the surface and the body is 0.8, then the ratio of the maximum height to which the bo 2025Two bodies of masses M and 4M initially at rest, start moving towards each other due to their mutual attraction. The velocity of their centre of mass when the first body attains a 2025A body of mass 2 kg is moving towards north with a velocity of 20 ~m ~s ⁻¹ and another body of mass 3 kg is moving towards east with a velocity of 10 ~m ~s ⁻¹ . The magnitude of th 2025A body of mass ' m ' moving along a straight line collides with a stationary body of mass ' 2 m '. After collision if the two bodies move together with the same velocity, then the 2025A disc of mass 0.2 kg is kept floating in air without falling by vertically firing bullets each of mass 0.05 kg on the disc at the rate of 10 bullets per every second. If the bulle 2025A body moving along a straight line collides another body of same mass moving in the same direction with half of the velocity of the first body. If the coefficient of restitution b 2025 Full Center of Mass, Momentum and Collision list All MHT CET PYQs