Question

Two bodies of masses 0.1 kg and 0.4 kg move towards each other with the velocities 1 m/s and 0.1 m/s respectively, After collision they stick together. In 10 sec the combined mass travels

• A. 120 m
• B. 0.12 m
• C. 12 m
• D. 1.2 m

Answer 1

Answer: (D)

1.2 m

Answer 2

Velocity of combined mass,

$v = \frac { m _ { 1 } v _ { 1 } - m _ { 2 } v _ { 2 } } { m _ { 1 } + m _ { 2 } }$= $\frac { 0.1 \times 1 - 0.4 \times 0.1 } { 0.5 } = 0.12 \mathrm {~m} / \mathrm { s }$

∴ Distance travelled by combined mass

=$v \times t =$ 0.12 × 10 = 1.2 m.