Question

Block A of ass m d block B of mass M are connected by a massless spring over a pulley on a rough olane with coefficient of friction as $\mu$. A force F is applied on block A to the left. Find the minimum value of M to move the block A towards right:

• A. $\frac{F}{2g}+\frac{\mu m}{2}$
• B. $\frac{F}{g}+\mu m$
• C. $\frac{F}{2g}+\mu m$
• D. $\frac{F}{2g}+2\mu m$

Answer 1

The correct option is B $\frac{F}{g}+\mu m$

Let x is expansion on the string it occur a force Kx

shown in the FBD diagram

$F+umg=kx$ ....eq1

$kx=Mg$ ....eq2

from eq1 and eq2

we get

$\Rightarrow M=\frac{F}{g}+\mu m$

Hence the B eq is correct.