A crate remains stationary after it has been placed on a ramp inclined at an angle with the horizontal. Which of the following statements is or are correct about the magnitude of the friction force that acts on the crate? Choose all that are true:
a. It is a larger than the weight of the crate
b. It is equal to u, n.
c. It is greater than the component of the gravitational force acting down the ramp.
d. It is equal to the component of the gravitational force acting down the ramp
e. It is less than the component of the gravitational force acting down the ramp.

d. It is equal to the component of the gravitational force acting down the ramp.

Explanation:

The stationary crate is inclined at an angle with the horizontal. The Recall, Frictional Force is any Force that opposes motion.

Because the Force of Friction that is opposing the motion of the crate along the inclination side.

Therefore this Frictional force is balanced or equal to the force that is driving the inclined force.

Hence Frictional Force is equal to the Gravitational Force that is acting in the ramp, that is why the crate is stationery.

1/0.14nm = 10^10/1.4 a lot

increase masses, decrease separation