Question

On the horizontal surface of a truck a block of mass $1kg$ is placed $(\mu =0.6)$ and truck is moving with acceleration $5m/{\sec }^2$ then the frictional force on the block will be

• A. 5 N
• B. 6 N
• C. 5.88 N
• D. 8 N

Answer 1

Answer: (A)

$f_{rl}={\mu }_{s}N={\mu }_s\times mg=0.6\times 1\times 10=6N.$
where $f_{rl}$ is the force of limiting friction.
Pseudo force $=ma=1\times 5;F=5N$
If $F<f_{rl}$, block does not move. So static friction is present.
Static friction = applied force .
$\therefore f_r=5N$.