A50-n crate sits on a horizontal floor where the coefficient of static friction between the crate and the floor is 0.50. a 20-n force is applied to the crate acting to the right. what is the resulting static friction force acting on the crate?

a. 20 n to the left.
b. 25 n to the left.
c. 25 n to the right.
d. none of the above; the crate starts to move.
e. 20 n to the right.

b. 25 N to the left.

Explanation:

Hi there!

The static friction force is calculated as follows:

Fr = N · μ

Where:

Fr = friction force.

N = normal force.

μ = coefficient of static friction.

If the object is not being accelerated in the vertical direction, the normal force is equal to the weight of crate (with opposite sign). Then:

Fr = 50 N · 0.50

Fr = 25 N

Since the 20-N force is applied to the right of the box, the friction force will be directed to the left because the friction force opposes the displacement. Then, the right answer is "b": 25 N to the left.

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force