Question

A worker pushes a box across the floor to the right at a constant speed with a force of 25N. What

can you conclude about the box? *

An unbalanced force of 25N is acting on the box.
Friction between the box and the floor is 25N to the left
The net horizontal force acting on the box is 50N.

Answer 1

C.Friction between the box and the floor is 25N to the left.

Step-by-step explanation:

One can conclude that the friction between the box and the floor is 25N to the left.

Frictional force is a force that opposes motion of a body. It acts in the opposite direction as the net force applied on a body.

• According to newton's third law of motion "action and reaction are equal and opposite in magnitude and direction".
• The action force is to right and the reaction force is to the left.

Answer 2

Friction between the box and the floor is 25N to the left

Step-by-step explanation:

There are two forces acting on the box along the horizontal direction:

- The force of push applied by the worker, in the forward direction, F

- The force of friction,
`F_f`, acting in the opposite direction (backward)

So the net force acting on the box is

`F_(net)=F-F_f`

According to Newton's second law of motion, the net force on an object is equal to the product between its mass (m) and its acceleration (a), so we can write:

`F_(net)=ma`

And so

`F-F_f = ma`

However, in this case the box is moving at constant speed; this means that its acceleration is zero:

`a=0`

Therefore we have:

`F-F_f=0`

Which means

`F_f=F`

And since we are told that

`F=25 N`

This means that the force of friction is also 25 N:

`F_f=F=25 N`