A block of mass m sits at rest on a rough inclined ramp that makes an angle θ with the horizontal.What must be true about force of static friction f on the block?
A)f mg
B)f mg cos θ
C)f mg sin θ
D)f = mg cos θ
E)f = mg sin θ

Question

A block of mass m sits at rest on a rough inclined ramp that makes an angle θ with the horizontal.What must be true about force of static friction f on the block?
A)f > mg
B)f > mg cos θ
C)f > mg sin θ
D)f = mg cos θ
E)f = mg sin θ

Quizplus · Accepted Answer

The force of static friction f must equal the component of gravitational force parallel to the incline, which is mg sin θ, to prevent the block from sliding down.

A Block of Mass M Sits at Rest on a Rough