Question

A block of mass mm is at rest on a rough incline. If the coefficient of static friction is 0.40 and the angle of inclination is 30∘, what force is exerted by friction?

A) mg
B) 0.4mg
C) 0.6mg
D) mgcos⁡(30∘)

Answer 1

The force exerted by friction on the block can be determined using the equation: force of friction = coefficient of friction × normal force.

Step-by-step explanation:

The force exerted by friction on the block can be determined using the equation:

force of friction = coefficient of friction × normal force

Here, the normal force is equal to the component of the weight of the block perpendicular to the incline, which can be calculated as:

normal force = mg × cosθ

where m is the mass of the block, g is the acceleration due to gravity, and θ is the angle of inclination. Therefore, the force exerted by friction is given by:

force of friction = μ × mg × cosθ

Substituting the values, we get:

force of friction = 0.40 × mg × cos(30°)