Question

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

Answer 1

Answer:

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

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:

$F_f=F=25 N$

Answer 2

Answer:

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

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.