Question

Use the table of information to answer the question.
Fruit Mass(kg) Speed (m/s)
Watermelon a 4 2
Watermelon b 4 4

Two watermelons fall off a kitchen counter. The masses and speeds of the fruits are in the table. How do the kinetic and/or the potential energies of the fruits compare?
A. Both fruits have only potential energy and no kinetic energy and no kinetic energy.
B. Both fruits have the same kinetic and potential energy.
C. The watermelon A has more kinetic energy.
D. The watermelon B has more kinetic energy.

Answer 1

To compare the kinetic and potential energies of the two watermelons, we can start by calculating their kinetic energy using the formula:

\[
KE = \frac{1}{2} mv^2
\]

where \( m \) is the mass and \( v \) is the speed of the object.

### For Watermelon A:
- Mass (\( m \)) = 4 kg
- Speed (\( v \)) = 2 m/s

Calculating the kinetic energy (KE) for Watermelon A:

\[
KE_A = \frac{1}{2} \times 4 \, \text{kg} \times (2 \, \text{m/s})^2 = \frac{1}{2} \times 4 \times 4 = \frac{1}{2} \times 16 = 8 \, \text{J}
\]

### For Watermelon B:
- Mass (\( m \)) = 4 kg
- Speed (\( v \)) = 4 m/s

Calculating the kinetic energy (KE) for Watermelon B:

\[
KE_B = \frac{1}{2} \times 4 \, \text{kg} \times (4 \, \text{m/s})^2 = \frac{1}{2} \times 4 \times 16 = \frac{1}{2} \times 64 = 32 \, \text{J}
\]

### Comparison of Kinetic Energies:
- Kinetic Energy of Watermelon A: \( 8 \, \text{J} \)
- Kinetic Energy of Watermelon B: \( 32 \, \text{J} \)

Thus, Watermelon B has more kinetic energy than Watermelon A.

### Potential Energy:
Both watermelons are falling, so they both have potential energy that depends on their height above the ground. However, the problem doesn't specify their heights, so we can't compare it based on the given data.

From the options provided, the correct choice regarding only kinetic energy is:

**D. The watermelon B has more kinetic energy.**