Question

select the correct answer.
a brick is lying on a table in a state of static equilibrium. if the mass of the brick is 7.52 kilograms, what is the normal force exerted by the table on the brick?
a. -73.7 newtons
b. 73.7 newtons
c. 80.7 newtons
d. 7.52 newtons
e. 8.07 newtons

Explanation:

Step1: Recall Newton's laws for equilibrium

In static equilibrium, the normal force \( F_N \) on the brick from the table balances the weight \( W \) of the brick. The weight is given by \( W = mg \), where \( m = 7.52 \, \text{kg} \) and \( g = 9.8 \, \text{m/s}^2 \) (approximate gravitational acceleration).

Step2: Calculate the weight (normal force)

Using the formula \( F_N=mg \), substitute \( m = 7.52 \) and \( g = 9.8 \):
\( F_N=7.52\times9.8 = 73.696\approx73.7 \, \text{newtons} \). The normal force is upward, balancing the downward weight, so it has a positive magnitude (direction is considered in sign, but magnitude here is positive as we calculate the force exerted by the table, upward).

Answer:

B. 73.7 newtons