Question

From the given figure we can conclude,

• A. Acceleration of 4 kg is $2m/s^2$
• B. Acceleration of 2 kg is $\frac{5}{3}m/s^2$
• C. Friction between 2kg & 4 kg is $\frac{4}{3}N$
• D. Friction force on 2 kg is opposite to force applied

Answer 1

Answer: (B), (C)

Friction between 2kg & 4 kg is $\frac{4}{3}N$

Say the bodies are moving together, then
$a=\frac{10N}{4+2}=\frac{10}{6}m/s^2$
Therefore, the net force on the 2 kg block is,
$2\times \frac{10}{6}=\frac{10}{3}N$

So, the friction on the 2 kg block is,
$\frac{10}{3}-2=\frac{4}{3}$
Limiting friction is,
$\mu N=0.6\times 20=18N$
The friction value is less than the limiting friction. Therefore, the assumption that the two bodies are moving together is correct, and our results are valid.