Question

Three identical blocks each having a mass m are pushed by a force F on a friction less table$.$ what is the acceleration of the blocks? what is the net force on the block P? hat force does p apply on $Q.$ what forces Q apply on $R?$

• A. $\frac{3F}{8}$
• B. $\frac{F}{7}$
• C. $\frac{F}{3}$
• D. $\frac{2F}{4}$

Answer 1

The correct option is C $\frac{F}{3}$

$\begin{array}{c}Supposethecommonacceleration=a\\ Totalmass=m+m+m=3m\\ Then,a=\frac{F}{3m}\\ NetforceonP=F_1=ma=m\times \frac{F}{3m}=\frac{F}{3}\\ ForceappliedonQbyp,\\ F_2=\left(m+m\right)a=2m\times \frac{F}{3m}=\frac{2F}{3}\\ ForceappliedonRbyQ,\\ F_3=ma=m\times \frac{F}{3m}=\frac{F}{3}\end{array}$

Hence,

option $\left(C\right)$ is correct answer.