Question

A person is trying to judge whether a picture (mass = 1.1 kg) is properly positioned by temporarily pressing it against a wall. The pressing force is perpendicular to the wall. What force does the picture exert on the wall?

a) 9.8 N
b) 11 N
c) 1.1 N
d) 0 N

Answer 1

The force that the picture exerts on the wall is equal in magnitude and opposite in direction to the force that the wall exerts on the picture. Therefore, the correct answer is d) 0 N.

Step-by-step explanation:

The force that the picture exerts on the wall is equal in magnitude and opposite in direction to the force that the wall exerts on the picture. According to Newton's third law of motion, every action has an equal and opposite reaction. Therefore, the force exerted by the picture on the wall is the same as the force exerted by the wall on the picture.

In this case, the weight of the picture can be calculated using the formula:

weight = mass × gravitational acceleration

Given that the weight of the picture is 51 N, we can rearrange the formula to solve for the mass:

mass = weight ÷ gravitational acceleration

Substituting the values, we have:

mass = 51 N ÷ 9.8 m/s² = 5.2 kg

Therefore, the force that the picture exerts on the wall is also 51 N, which is equivalent to 5.2 kg multiplied by the acceleration due to gravity. The correct answer is d) 0 N.