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?(1 point)
Responses

Both fruits have the same kinetic and potential energy.
Both fruits have the same kinetic and potential energy.

Both fruits have only potential energy and no kinetic energy.
Both fruits have only potential energy and no kinetic energy.

The watermelon A has more kinetic energy.
The watermelon A has more kinetic energy.

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

1 answer

To compare the kinetic and potential energies of Watermelon A and Watermelon B, we can use the formulas for kinetic energy (KE) and potential energy (PE).

  1. Kinetic Energy (KE) is calculated using the formula: \[ KE = \frac{1}{2} mv^2 \] where \( m \) is the mass in kilograms and \( v \) is the speed in meters per second.

  2. Potential Energy (PE) depends on the height from which the watermelons fall. Since it is not specified in the question, we can assume both watermelons have the same height at the moment they fall, which would mean they have the same potential energy.

Now let's calculate the kinetic energy for each watermelon.

For Watermelon A:

  • Mass (\( m \)) = 4 kg
  • Speed (\( v \)) = 2 m/s \[ KE_A = \frac{1}{2} \times 4 \times (2^2) = \frac{1}{2} \times 4 \times 4 = 8 , \text{Joules} \]

For Watermelon B:

  • Mass (\( m \)) = 4 kg
  • Speed (\( v \)) = 4 m/s \[ KE_B = \frac{1}{2} \times 4 \times (4^2) = \frac{1}{2} \times 4 \times 16 = 32 , \text{Joules} \]

Now we can summarize:

  • Both watermelons have the same mass, thus potential energy is the same as long as they start from the same height.
  • Watermelon A has a kinetic energy of 8 Joules.
  • Watermelon B has a kinetic energy of 32 Joules.

Conclusion:

  • Potential Energy: Both fruits have the same potential energy (assuming they are at the same height).
  • Kinetic Energy: Watermelon B has more kinetic energy (32 Joules) compared to Watermelon A (8 Joules).

Based on these comparisons, the correct response is:

The watermelon B has more kinetic energy.