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?

49 N

We are given;

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

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

increases it

heats surface water up