A person pushes horizontally with a force of 270 N on a 55 kg crate to move it across a level floor. The coefficient of kinetic friction is 0.25.

What is the magnitude of the frictional force? What is the magnitude of the crate's acceleration?

frictionforce=mu*mg=.25*55*9.8 N

net force= ma
270-frictionalforce= mass*a
solve for a

To find the magnitude of the frictional force, we can use the equation:

frictional force = coefficient of friction * normal force

The normal force is the force exerted by the floor on the crate and is equal to the weight of the crate. We can find the weight using the equation:

weight = mass * gravity

where the mass of the crate is 55 kg and the acceleration due to gravity is approximately 9.8 m/s^2.

Substituting the values, we have:

weight = 55 kg * 9.8 m/s^2 = 539 N

Now we can find the frictional force:

frictional force = 0.25 * 539 N = 134.75 N

Therefore, the magnitude of the frictional force is approximately 134.75 N.

To find the magnitude of the crate's acceleration, we can use the equation:

net force = mass * acceleration

The net force is the difference between the applied force and the frictional force:

net force = applied force - frictional force = 270 N - 134.75 N = 135.25 N

Now we can find the acceleration:

135.25 N = 55 kg * acceleration

acceleration = 135.25 N / 55 kg = 2.46 m/s^2

Therefore, the magnitude of the crate's acceleration is approximately 2.46 m/s^2.