Question

Two rigid bodies of mass $5kg$ and $4kg$ are at rest on a frictionless surface until acted upon by a force of $36N$ as shown in the figure. The contact force generated between the two bodies is

• A. $4.0N$
• B. $7.2N$
• C. $9.0N$
• D. $16.0N$

Answer 1

The correct option is D $16.0N$


Net force $=$ Net mass $\times$ acceleration
$\Rightarrow 36=9\times a$
$\Rightarrow a=4m{s}^{-2}$
Now, considering $5kg$ weight only force on $5kg=5\times 4N=20N$


$\Rightarrow 36N-F=20N$
$\Rightarrow F=16N$