Question

The frictional force acting on $1kg$ block will be:

• A. $0.1\text{N}$
• B. $2\text{N}$
• C. $5\text{N}$
• D. $7.5\text{N}$

Answer 1

The correct option is A $0.1\text{N}$

The FBD of system & FBD for individual block of $1kg$ is presented below:

If both blocks move move together, then $a=\frac{F}{m_{system}}=\frac{10}{101}\simeq 0.1m/s^2$
Now for $1kg$ block, $f=m\times a=1\times 0.1=0.1N$

Limiting value of friction $f_l=\left(0.5\right)\left(1\right)\left(g\right)=5N$

We find that $f\le f_L$
$\therefore$ frictional force on $1kg$ block is $f$= $0.1N$