Question

A truck of mass 10 metric ton runs at $3m{s}^{-1}$ along a level track and collides with a loaded truck of mass 20 metric ton, standing at rest. If the trucks couple together, the common speed after collision is

• A. $1m{s}^{-1}$
• B. $10m{s}^{-1}$
• C. $0.5m{s}^{-1}$
• D. $0.3m{s}^{-1}$

Answer 1

Answer: (A)

$1m{s}^{-1}$

Using momentum conservation
$10\times 3=0\times 20+30\times v$
$\Rightarrow v=1m/s$