Question

Maximum acceleration of the train in which a $50kg$ box lying on its floor will remain stationary is(Given : Co-efficient of static friction between the box and the train's floor is $0.13$ and $g=9.8m{s}^{-2}$):

• A. $5.0m{s}^{-2}$
• B. $3.0m{s}^{-2}$
• C. $1.5m{s}^{-2}$
• D. $15m{s}^{-2}$

Answer 1

The correct option is B $3.0m{s}^{-2}$

Given: $\mu =0.3$ $m=30$ kg

The box kept on the floor of train remains stationary if the pseudo force acting on the box is balanced by friction force.

Friction force, $f=\mu mg$

$\therefore$ $ma=\mu mg$ where $a$ is the maximum acceleration of train

$⟹$ $a=\mu g=0.3\times 10=3.0$ $m/s^2$