Question

What force is needed to keeps 20kg box moving at a constant velocity when the mk is 0.3021 and the force is applied level to the ground

Answer 1

59.2 N

Step-by-step explanation:

According to Newton's second law, the resultant of the forces acting on the box must be equal to the product between the box's mass and its acceleration:

`F_(net)=ma`

However, the box is moving at constant velocity, so its acceleration is zero:

a = 0

Therefore, the net force along the direction of motion (parallel to the surface) must be zero.

We have two forces acting along the direction parallel to the ground:

- The applied force, F

- The frictional force,
`\mu mg`, in the opposite direction, with
`\mu = 0.3021` being the coefficient of friction, m = 20 kg the mass of the box and g = 9.8 m/s^2

Therefore, the equation of motion becomes:

`F-\mu mg=0`

And solving for F, we find:

`F=\mu mg=(0.3021)(20 kg)(9.8 m/s^2)=59.2 N`