Question

Two blocks are in contact on a frictionless table. One has a mass $m$ and the other $2m$. A force $F$ is applied on $m$.
In the two cases respectively the ratio of force of contact between the two blocks will be:

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

Answer 1

Answer: (B)

If $F$ is the applied force then acceleration of the system is $\frac{F}{2m+m}=\frac{F}{3m}$

Now when we apply the force from the left, the force applied on the block $m$ is $\frac{F}{3m}m=\frac{F}{3}$. This will be the force in the contact.

When we apply the force from the right from on the block will be $\frac{F}{3m}2m=\frac{2F}{3}$, this will be the force on the contact then.

So the ratio is $\frac{F}{3}:\frac{2F}{3}=1:2$

Hence,

option $B$ is correct answer.