a person pushes a 10kg mass at a constant speed across a u=0.150, 8.50m long floor at a constant speed

how much work does the person do? (125J)
how much work does friction do? ( -125J)

The friction force is M g u = 10*9.81*.15 = 14.7 N

Multiply Force x distance for work done. That would be 14.7 x 8.5 = 125 J

Friction has the work done on it, and is therefore equal and opposite

To calculate the work done by the person, we can use the equation:

Work = Force × Distance × cos(θ)

Where:
- Force is the force applied by the person
- Distance is the distance over which the force is applied
- θ is the angle between the direction of the force and the direction of motion

In this case, the force applied by the person is equal to the force needed to overcome friction. Since the object is moving at a constant speed, the force applied by the person must be equal in magnitude and opposite in direction to the force of friction.

First, let's find the force of friction using the equation:

Force of friction = coefficient of friction × normal force

The normal force is equal to the weight of the object, which can be calculated as:

Normal force = mass × gravity

Given:
- Mass = 10 kg
- u = 0.150 (coefficient of friction)
- Distance = 8.50 m

Now, let's calculate the normal force:

Normal force = 10 kg × 9.8 m/s^2

Next, we can calculate the force of friction:

Force of friction = 0.150 × (10 kg × 9.8 m/s^2)

Now that we have the force of friction, let's calculate the work done by the person:

Work = (-1) × Force of friction × Distance

Since the force applied by the person is in the opposite direction to the displacement, we multiply by (-1).

Work = (-1) × (force of friction) × 8.50 m

After performing the calculations, we find that the work done by the person is 125 J (Joules).

To find the work done by friction, we can simply note that it is equal in magnitude and opposite in sign to the work done by the person. Therefore, the work done by friction is -125 J.