Question

A block of mass m is in contact with the cart as shown in figure
The coefficient of static friction between the block and the cart is . The acceleration of the cart that will prevent the block from falling satisfies

• A. $\alpha >\frac{mg}{\mu }$
• B. $\alpha >\frac{g}{\mu m}$
• C. $\alpha \ge \frac{g}{\mu }$
• D. $\alpha <\frac{g}{\mu }$

Answer 1

The correct option is C $\alpha \ge \frac{g}{\mu }$

Fig. shows all the forces acting on a block of mass m.

$m\alpha =$ pseudo force

frictional force, $f_s\ge mg$

$\mu N\ge mg$

$\mu m\alpha \ge mg$

$\alpha \ge \frac{g}{\mu }$