AP EAMCET202422 May 2024Evening ShiftPhysicsCenter of Mass, Momentum and CollisionActual
A body of mass 30 kg moving with a velocity 20 ~ms ⁻¹ undergoes one dimensional elastic collision with another ball of same mass moving in the opposite direction with a velocity of 30 ~ms ⁻¹ . After collision the velocities of first and second bodies respectively are
Options
- A25 ~ms ⁻¹, 30 ~ms ⁻¹
- B30 ~ms ⁻¹, 30 ~ms ⁻¹
- C30 ~ms ⁻¹, 20 ~ms ⁻¹
- D40 ~ms ⁻¹, 15 ~ms ⁻¹
Correct answer
C. 30 ~ms ⁻¹, 20 ~ms ⁻¹
Step-by-step solution
m₁=m₂=30 ~kg , u₁=20 ~m / s , u₂=-30 ~m / s By conservation of momentum, aligned & m ₁ u ₁+ m ₂ u ₂= m ₁ v ₁+ m ₂ v ₂ & 20-30= v ₁+ v ₂ aligned v ₁+ v ₂=-10 ... (i) Also, v ₂- v ₁=e ( u ₁- u ₂ )=1 (20-(-30)) -v₁+v₂=50 ... (ii) From eq (i) and (ii), we get aligned & 2 v₂=40 v₂=20 ~m / s & v₁=v₂-50=20-50=-30 ~m / s aligned Two bodies moves with velocity 30 ~m / s & 20 ~m / s in opposite directions.