Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEETPhysicsCenter of Mass, Momentum and Collision

A ball of mass 0.2 kg is dropped from a height of 20 m . Upon striking the ground, the ground imparts an upward impulse of 12 N s to the ball. The height to which the ball rebounds is (g = 10 m s ⁻²) :

Options

  1. A180 m
  2. B80 m
  3. C320 m
  4. D20 m

Correct answer

B. 80 m

Step-by-step solution

Velocity of the ball just before striking the ground: v₁ = 2gh₁ = 2 10 20 = 20 m s ⁻¹ (downwards) Taking the upward direction as positive, the initial momentum of the ball is: p_i = m(-v₁) = 0.2 (-20) = -4 kg m s ⁻¹ According to the impulse-momentum theorem: J = p_f - p_i 12 = p_f - (-4) 12 = p_f + 4 p_f = 8 kg m s ⁻¹ The rebound velocity v₂ is: v₂ = p_f m = 8 0.2 = 40 m s ⁻¹ (upwards) The height to which the ball rebounds is: h₂ = v₂^2 2g = 40^2 2 10 = 1600 20 = 80 m Answer: 80 m

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

More from Center of Mass, Momentum and Collision

A frictionless circular wire of unit radius is fixed on the horizontal plane. Two point particles of unit mass start moving simultaneously from point A ( = 2 ) with identical unifo 2026Bob B of mass m at rest is hanging vertically from the ceiling via a massless string of length 10 m, as shown in the figure. Point mass A of mass m travelling horizontally with spe 2026A ball of mass 0.5 kg is dropped from a height of 40 m . The ball hits the ground and rises to a height of 10 m . The impulse imparted to the ball during its collision with the gro 2025Two bodies A and B of same mass undergo completely inelastic one dimensional collision. The body A moves with velocity v₁ while body B is at rest before collision. The velocity of 2024Two particles A and B initially at rest, move towards each other under mutual force of attraction. At an instance when the speed of A is v and speed of B is 3 v , the speed of cent 2023A 1 ~kg object strikes a wall with velocity 1 ~ms ⁻¹ at an angle of 60^ with the wall and reflects at the same angle. If it remains in contact with wall for 0.1 ~s , then the force 2023A bullet of mass m hits a block of mass M elastically. The transfer of energy is the maximum, when 2023A shell of mass m is at rest initially. It explodes into three fragments having mass in the ratio 2 : 2 : 1 . If the fragments having equal mass fly off along mutually perpendicula 2022 Full Center of Mass, Momentum and Collision list All NEET PYQs