Question

9. A block of wood is placed on a surface. A force is applied parallel to the surface
to move the body. The frictional force developed acts
(a) normal to the surface upwards
(b) normal to the surface downwards
(e) along the direction of the applied force
(d) opposite to the direction of the applied force​

Answer 1

Answer:

d. opposite to the direction of the applied force

Explanation:

Friction always oppose the relative slipping between two bodies

So it oppose the motion of block so that block is at rest

Answer 2

$\large \green{ \underline{ \sf \: Answer : - }}$

$\sf \: friction \: force \: always \: oppose \: the \:$

$\sf applied \: force$

$\sf \: Hence \: frictional \: force \: acts \: opposite \: to$

$\sf \: the \: direction \: of \: the \: applied \: force.$

$\sf \: option \: \green{d} \: is \: correct$