You are pulling a 60-kg crate across a level floor with a rope. If a force of 200 N

on the rope gives the crate an acceleration of 2 m/s2, what is the force of friction
that the crate exerts on the floor?

ma=F-F(fr)

F(fr)=F+ma = 200 +60•2 =320 N

To find the force of friction, we need to use Newton's second law of motion, which states that the force (F) acting on an object is equal to the mass (m) multiplied by the acceleration (a). In this case, the force acting on the crate is the force from the rope pulling it, and the acceleration is given.

Given:
Mass of the crate (m) = 60 kg
Acceleration (a) = 2 m/s²
Force from the rope (F) = 200 N

Using Newton's second law of motion, we can rearrange the formula to solve for the force of friction (F_friction) exerted by the crate on the floor.

F = m * a

Rearranging the formula:

F_friction = F - F_rope

Substituting the given values into the equation:

F_friction = m * a - F_rope
F_friction = 60 kg * 2 m/s² - 200 N

Calculating the force of friction:

F_friction = 120 kg·m/s² - 200 N
F_friction = 120 N - 200 N
F_friction = -80 N

The negative sign indicates that the force of friction is in the opposite direction as the applied force, as it acts to oppose the motion. Therefore, the force of friction exerted by the crate on the floor is 80 N.