A stressed out Mom just purchased a cup of Starbucks coffee. The bus she is riding on to work goes around a sharp curve. Even though she holds the cup still, the coffee still splashes out. Which word explains this phenomenon?
A. Gravity
B. Inertia
C. Friction
D. Density
B. Inertia
The word that explains this phenomenon is B. Inertia.
Inertia is the tendency of an object to resist changes in its motion. In this case, when the bus goes around the sharp curve, the mom's body (and also the coffee cup) wants to continue moving in a straight line due to inertia. However, the bus's change in direction pulls her body (and the coffee) towards the outside of the turn. Even though she holds the cup still, the coffee still splashes out due to the inertia pulling it towards the outside of the turn.
The word that explains this phenomenon is B. Inertia.
Inertia is the tendency of an object to resist changes in its state of motion. In this case, when the bus goes around the sharp curve, the mom and her cup of coffee are both in motion. Because of inertia, the coffee wants to keep moving in a straight line, while the bus is changing direction. As a result, the cup is forced to move sideways relative to the mom, causing the coffee to splash out.
To better understand why inertia is the correct answer, let's briefly explain the other options:
A. Gravity: Gravity is the force that attracts objects towards each other. While gravity plays a role in keeping the coffee in the cup while the bus is not in motion, it is not the main cause of the coffee splashing out during the sharp curve.
C. Friction: Friction is the force that resists the motion of two objects sliding against each other. While friction may contribute to some spillage if the cup is rubbed against an external surface, it is not the primary reason for the coffee splashing out during the bus curve.
D. Density: Density is a measure of how much mass is in a given volume. It does not directly explain why the coffee splashes out during the bus curve.
In conclusion, the correct answer is B. Inertia, which explains how the coffee spills due to the tendency of the cup to resist changing its state of motion while the bus is turning sharply.