Two blocks of masses $m_{1}$ and $m_{2}$ are placed in contact with each other on a horizontal platform as shown in figure. The coefficient of friction between $m_{1}$ and platform is $2 μ$ and that between block $m_{2}$ and platform is $μ$ . The platform moves with an acceleration a. The normal reaction between the blocks is

see full answer

Talk to JEE/NEET 2025 Toppers - Learn What Actually Works!

Real Strategies. Real People. Real Success Stories - Just 1 call away

An Intiative by Sri Chaitanya

zero in all cases

zero only if $m_{1} = m_{2}$

non zero only if $a > 2 μ g$

non zero only if $(a > μ g)$

answer is D.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

Maximum friction available to $m_{2}$ is

$(f_{\max}) = μ m_{2} g$

Therefore, maximum acceleration which can be provided to $m_{2}$ by friction, without the help of normal reaction from $m_{1}$ is

$a_{\max} = \frac{f_{lnax}}{m_{2}} = μ g$

If $a > μ g$ , normal reaction from $m_{1}$ on ${m_{2}}_{}$ is non zero.

Watch 3-min video & get full concept clarity

JEE

NEET

Foundation JEE

Foundation NEET

CBSE