Question 239: Laws of Motion

Question

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

Accepted Answer

Forces acting on the block are as shown in
the fig. Normal reaction N is provided by the
force ma due to acceleration $$\alpha $$
$$ 	herefore $$ N = m$$\alpha $$
For the block not to fall, frictional force, $${F_f} \ge mg$$
$$ \Rightarrow \mu N \ge mg$$
$$ \Rightarrow \mu m\alpha  \ge mg$$
$$ \Rightarrow \alpha  \ge g/\mu $$

Answer

$$\alpha  > {{mg} \over \mu }$$

Answer

$$\alpha  > {g \over {\mu m}}$$

Answer

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

Answer

$$\alpha  < {g \over \mu }$$

Laws of Motion

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

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