A block weighs W is held against a vertica

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A block weighs $W$ is held against a vertical wall by applying a horizontal force $F$. The minimum value of $F$ needed to hold the block is

A

Less than $W$

B

Equal to $W$

C

Greater than $W$

D

Data is insufficient

A block weighs $W$ is held against a vertical wall by applying a horizontal force $F$. The minimum value of $F$ needed to hold the block is

Here applied horizontal force $F$ acts as normal reaction.

For holding the blockForce of friction = Weight of block

$f = W$  $⇒$  $\mu \,R = W$  $⇒$  $\mu \,F = W$  

$⇒$  $F = \frac{W}{\mu }$         As $\mu < 1$ 

$\therefore \;\;\;F > W$