Question

Three blocks of masses $3kg,2kg$ and $1kg$ are placed side by sides on a smooth surface as shown in figure. A horizontal force of $12N$ is applied on $3kg$ block then the net force on $2kg$ block will be

• A. $1N$
• B. $2N$
• C. $3N$
• D. $4N$

Answer 1

Answer: (D)

$4N$

Given,

$Mass=3kg,2kg,1kg$ $f=12N$

Since $12N$ is applied on the total mass $=2+3+1=6kg$

$\Rightarrow a=\frac{f}{m}=\frac{12}{6}=2m/s^2$

Therefore $2kg$ also moves with $2m/s^2$

Thus the net force $F_{net}=m\times a=2\times 2=4N$