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3 years ago

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A box rests on the floor. If you pull sideways on the box with a 300 N force, but don't move it, what is the magnitude of the fr

ictional force? A. 0 N B. 300 N C. less than 300 N D. more than 300 N

1 answer:

Dahasolnce [82]3 years ago

5 0

The magnitude of the frictional force is B) 300 N

Explanation:

For this problem, we just have to consider the forces acting on the box in the horizontal direction.

There are only two forces in this direction:

- The pull applied by the man, of magnitude F=300 N, forward

- The frictional force, $F_f$ , acting backward

So the equation of motion for the box is

$F-F_f = ma$

where

m is the mass of the box

a is its acceleration

However, the box is at rest, so its acceleration is zero:

a = 0

This means therefore that

$F-F_f=0$

And so the magnitude of the frictional force is equal to the pulling force:

$F_f = F = 300 N$

Learn more about friction:

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