Question

A rough vertical board has an acceleration $a$ so that a $2kg$ block pressing against it does not fall. The coefficient of friction between the block and the board should be

• A. $>g/a$
• B. $<g/a$
• C. $=g/a$
• D. $>a/g$

Answer 1

The correct option is A $>g/a$

frictional force=$\mu N$

$\mu ma=mg$

$\mu =\frac{g}{a}$