Laws Of Motion Question 275
Question: Three blocks A, B and C of masses 4 kg, 2 kg and 1 kg respectively, are in contact on a motionless surface, as shown. If a force of 14 N is applied on the 4 kg block then the contact force between A
Options:
A) 6 N
B) 8 N
C) 18 N
D) 2 N
Show Answer
Answer:
Correct Answer: A
Solution:
[a] Acceleration of system $ a=\frac{F _{net}}{M _{total}} $
$ =\frac{14}{4+2+1}=\frac{14}{7}=2\text{ m/}{{m}^{2}} $
The contact force between A and B $ =( m _{B}+m _{C} )\times a=( 2+1 )\times 2=6\text{ N} $
