Inelastic Collision — NEET Physics MCQs with Solutions
Free NEET Physics Inelastic Collision MCQs with step-by-step solutions (20 questions). Part of Collision. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Inelastic Collision · easy · numerical
A 4 kg ball moving at 9 m/s collides with a 2 kg ball at rest and the two stick together. What is their common velocity just after the collision?
A. 9 m/s
B. 3 m/s
C. 4.5 m/s
D. 6 m/s ✓ Correct
Solution: By momentum conservation, v = m₁u₁/(m₁ + m₂) = (4 × 9)/6 = 6 m/s.
Q2 — Inelastic Collision · easy · numerical
A 1 kg body moving at 10 m/s strikes a 4 kg body at rest and embeds in it. Find the velocity of the combined mass.
A. 2.5 m/s
B. 2 m/s ✓ Correct
C. 5 m/s
D. 4 m/s
Solution: v = m₁u₁/(m₁ + m₂) = (1 × 10)/5 = 2 m/s.
Q3 — Inelastic Collision · easy · numerical
A 5 kg block sliding at 12 m/s on a smooth surface hits a 1 kg block at rest and the two move off together. What is their common speed?
A. 12 m/s
B. 10 m/s ✓ Correct
C. 8 m/s
D. 6 m/s
Solution: v = m₁u₁/(m₁ + m₂) = (5 × 12)/6 = 10 m/s.
Q4 — Inelastic Collision · easy · numerical
A 3 kg ball moving at 5 m/s collides head-on with a 2 kg ball moving at 5 m/s in the opposite direction. If they stick together, what is the speed of the combined mass?
A. 5 m/s
B. 0.5 m/s
C. 2 m/s
D. 1 m/s ✓ Correct
Solution: Net momentum = 3 × 5 − 2 × 5 = 5 kg·m/s, so v = 5/(3 + 2) = 1 m/s along the initial direction of the 3 kg ball.
Q5 — Inelastic Collision · easy · numerical
A 3 kg trolley moving at 11 m/s catches up with another 3 kg trolley moving at 7 m/s in the same direction and couples with it. Find their common velocity.
A. 4 m/s
B. 8 m/s
C. 9 m/s ✓ Correct
D. 18 m/s
Solution: v = (m₁u₁ + m₂u₂)/(m₁ + m₂) = (33 + 21)/6 = 9 m/s.
Q6 — Inelastic Collision · easy · numerical
A 40 g bullet moving at 200 m/s embeds itself in a 1.96 kg block resting on a smooth floor. With what speed does the block (with the bullet) start moving?
A. 5 m/s
B. 2 m/s
C. 4 m/s ✓ Correct
D. 8 m/s
Solution: v = m₁u₁/(m₁ + m₂) = (0.04 × 200)/2.00 = 8/2 = 4 m/s.
Q7 — Inelastic Collision · easy · numerical
A 6 kg body moving at 3 m/s collides with a 3 kg body at rest and they stick together. How much kinetic energy is lost in the collision?
A. 18 J
B. 13.5 J
C. 9 J ✓ Correct
D. 27 J
Solution: v = 18/9 = 2 m/s, so KE loss = ½ × 6 × 3² − ½ × 9 × 2² = 27 − 18 = 9 J.
Q8 — Inelastic Collision · easy · numerical
A 2 kg ball moving at 8 m/s strikes a 6 kg ball at rest and the two stick together. What percentage of the initial kinetic energy is lost?
A. 37.5%
B. 50%
C. 25%
D. 75% ✓ Correct
Solution: v = 16/8 = 2 m/s; KE falls from 64 J to ½ × 8 × 2² = 16 J, so 48/64 = 75% is lost (= m₂/(m₁ + m₂) = 6/8).
Q9 — Inelastic Collision · easy · numerical
A 2 kg body moving at 15 m/s undergoes a perfectly inelastic collision with a 4 kg body at rest. What fraction of the initial kinetic energy is lost?
A. 1/3
B. 1/2
C. 2/3 ✓ Correct
D. 1/4
Solution: Fraction lost = m₂/(m₁ + m₂) = 4/6 = 2/3; check: v = 30/6 = 5 m/s, KE drops from 225 J to 75 J, and 150/225 = 2/3.
Q10 — Inelastic Collision · easy · numerical
A 20 g bullet moving at 300 m/s embeds in a 2.98 kg block suspended as a ballistic pendulum. To what height does the block rise? (g = 10 m/s²)
A. 0.2 m ✓ Correct
B. 0.4 m
C. 0.1 m
D. 0.8 m
Solution: v = (0.02 × 300)/3.00 = 2 m/s, so h = v²/2g = 4/20 = 0.2 m.
Q11 — Inelastic Collision · easy · numerical
A 5 kg body moving at 6 m/s collides with a 1 kg body at rest and the two move together after impact. Find their common velocity.
A. 2.5 m/s
B. 5 m/s ✓ Correct
C. 6 m/s
D. 3 m/s
Solution: v = m₁u₁/(m₁ + m₂) = (5 × 6)/6 = 5 m/s.
Q12 — Inelastic Collision · easy · numerical
A 2 kg ball moving at 10 m/s hits a 3 kg ball at rest and sticks to it. What is the kinetic energy of the combined mass just after the collision?
A. 20 J
B. 40 J ✓ Correct
C. 100 J
D. 60 J
Solution: v = 20/5 = 4 m/s, so KE = ½ × 5 × 4² = 40 J (down from the initial 100 J).
Q13 — Inelastic Collision · medium · numerical
A 3 kg ball moving east at 2 m/s collides with a 2 kg ball moving north at 4 m/s. They stick together on impact. What is the speed of the combined mass?
A. 2.8 m/s
B. 2 m/s ✓ Correct
C. 3 m/s
D. 1.2 m/s
Solution: Momentum components are 3 × 2 = 6 and 2 × 4 = 8 kg·m/s, giving resultant √(6² + 8²) = 10 kg·m/s, so v = 10/5 = 2 m/s.
Q14 — Inelastic Collision · medium · numerical
Two 4 kg bodies moving toward each other at 7 m/s and 1 m/s collide and stick together. How much kinetic energy is lost in the collision?
A. 64 J ✓ Correct
B. 100 J
C. 50 J
D. 36 J
Solution: v = (28 − 4)/8 = 3 m/s; KE drops from ½ × 4 × 7² + ½ × 4 × 1² = 100 J to ½ × 8 × 3² = 36 J, a loss of 64 J.
Q15 — Inelastic Collision · medium · numerical
A 50 g bullet fired into a 1.95 kg ballistic-pendulum block embeds in it, and the block rises 0.45 m. Find the speed of the bullet. (g = 10 m/s²)
A. 90 m/s
B. 60 m/s
C. 240 m/s
D. 120 m/s ✓ Correct
Solution: The block-bullet speed is v = √(2gh) = √(2 × 10 × 0.45) = 3 m/s, so u = (2.00 × 3)/0.05 = 120 m/s.
Q16 — Inelastic Collision · medium · numerical
A 6 kg cart moving at 7 m/s catches up with a 4 kg cart moving at 2 m/s in the same direction and locks onto it. How much kinetic energy is dissipated?
A. 30 J ✓ Correct
B. 125 J
C. 15 J
D. 50 J
Solution: v = (42 + 8)/10 = 5 m/s; KE drops from 147 + 8 = 155 J to ½ × 10 × 5² = 125 J, so 30 J is dissipated.
Q17 — Inelastic Collision · medium · numerical
A 1 kg ball moving at 5 m/s strikes a 4 kg ball at rest and sticks to it. What percentage of the initial kinetic energy is converted to heat and sound?
A. 80% ✓ Correct
B. 60%
C. 40%
D. 20%
Solution: Fraction lost = m₂/(m₁ + m₂) = 4/5 = 80%; check: v = 5/5 = 1 m/s, KE falls from 12.5 J to 2.5 J.
Q18 — Inelastic Collision · medium · numerical
A 6 kg ball moving at 6 m/s collides with a 3 kg ball at rest and the two stick together. What impulse does the 3 kg ball receive?
A. 24 N·s
B. 12 N·s ✓ Correct
C. 6 N·s
D. 36 N·s
Solution: v = 36/9 = 4 m/s, so the impulse on the 3 kg ball = m₂v = 3 × 4 = 12 N·s (equal to the 6 kg ball losing 6 × 2 = 12 kg·m/s).
Q19 — Inelastic Collision · medium · numerical
A 4 kg body moving at 12 m/s collides with a stationary body, sticks to it, and the combination moves at 8 m/s. What is the mass of the second body?
A. 3 kg
B. 4 kg
C. 2 kg ✓ Correct
D. 6 kg
Solution: Momentum conservation: 4 × 12 = (4 + m) × 8, so 4 + m = 6 and m = 2 kg.
Q20 — Inelastic Collision · medium · numerical
A 2 kg ball moving at 7 m/s collides head-on with a 1 kg ball moving at 2 m/s in the opposite direction, and they stick together. How much heat is generated in the collision?
A. 27 J ✓ Correct
B. 13.5 J
C. 24 J
D. 51 J
Solution: v = (14 − 2)/3 = 4 m/s; KE drops from 49 + 2 = 51 J to ½ × 3 × 4² = 24 J, so 27 J becomes heat.