Laws Of Motion Question 335
Question: A block A of mass 4 kg is placed on another block B of mass 5 kg, and the block B rests on a smooth horizontal table. If the minimum force that can be applied on A so that both the blocks move together is 12 N, the maximum force that can be applied to B for the blocks to move together will be:
Options:
A) 30 N
B) 25 N
C) 27 N
D) 48 N
Show Answer
Answer:
Correct Answer: C
Solution:
[c] Minimum force on A =frictional force between the surfaces = 12 N
Therefore maximum acceleration $ {a _{\max }}=\frac{12N}{4kg}=3m/s^{2} $
Hence maximum force, $ {{F} _{max}}=totalmass\times a _{max}=9\times 3=27N $
