Question

A block $P$ of mass $m$ is placed on a horizontal frictionless plane. A second block of same mass $m$ is placed on it and is connected to a spring of spring constant $k$, the two blocks are pulled by distance $A$. Block $Q$ oscillates without slipping. What is the maximum value of frictional force between the two blocks

• A. $kA/2$
• B. $kA$
• C. ${\mu }_{s}mg$
• D. $zero$

Answer 1

Answer: (A)

$kA/2$

$a_{max}=\frac{k}{2m}A$

Hence, $f_{max}=m{a}_{max}=\frac{kA}{2}$