Question

2. A woman prevents a 3kg brick from falling by pressing it against a vertical wall. The coefficient of friction
is 0.6
a. What force must she use?

Answer 1

Answer:

49 N

Explanation:

We are given;

• Mass of the brick as 3 kg
• The coefficient of friction as 0.6

We are required to determine the force that must be applied by the woman so the brick does not fall.

• We need to importantly note that;
• For the brick not to fall the, the force due to gravity is equal to the friction force acting on the brick.

• That is; Friction force = Mg

But; Friction force = μ F

Therefore;

μ F = mg

0.6 F = 3 × 9.8

0.6 F = 29.4

      F = 49 N

Therefore, she must use a force of 49 N