Question

A cup of coffee has a mass of 0.404 kg. If you place this cup of coffee on a desk and let is sit there undisturbed, how much force is the desk exerting on it?

Answer 1

Given:

Mass of cup = 0.404 kg

If the cup is placed on a desk and it sit there undisturbed, let's determine how much force the desk will exert on it.

Given that the cup is left undisturbed, the Earth applies a gravitational force on the cup.

The desk will exert a force which is equal to the magnitude of the weight of the cup, and also in opposite direction (normal reaction).

Thus, to find the force, apply the formula:

F = m x g

Where:

• F is the force

,

• m is the mass = 0.404 kg

,

• g is acceleration due to gravity = 9.8 m/s²

Thus, we have:

`\begin{gathered} F=m*g \\ \\ F=0.404*9.8 \\ \\ F=3.96\text{ N} \end{gathered}`

Therefore, the force the desk is exerting on the cup is 3.96 N.

ANSWER:

3.96 N