Question

Two blocks are in contact on a frictionless table. One has mass m and the other 2 m. A force F is applied on 2 m as shown in the figure. Now the same force F is applied from the right on m. In the two cases respectively, the ratio of the force of contact between the two blocks will be :

• A. Same
• B. 1 : 2
• C. 2 : 1
• D. 1 : 3

Answer 1

The correct option is(B):1 : 2

If $F$ is the applied force then acceleration of the system is

$\frac{F}{2m+m}=\frac{F}{3m}$

Now when we are applying the force from the left,the force applied on the block m is

$\frac{F}{m+2m}\times m=\frac{F}{3}$

This will be the force in the contact from left.

When we apply the force from the right from onthe block will be

$\frac{F}{m+2m}\times 2m=\frac{2F}{3}$

this will be the forceon the contact from right side.

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