Use the image to answer the question.

An illustration shows a person running after a rabbit. The person weighs 60 kilograms, and the rabbit weighs 4 kilograms. The speed of both is 5 meters per second.

A wildlife keeper is trying to catch an escaping rabbit. Who has the greater kinetic energy, the rabbit or the wildlife keeper?

(1 point)
Responses

The rabbit because it has less mass.
The rabbit because it has less mass.

Neither one because they are moving at the same speed.
Neither one because they are moving at the same speed.

The wildlife keeper because they speed up and catch the rabbit.
The wildlife keeper because they speed up and catch the rabbit.

The wildlife keeper because they have a greater mass.

1 answer

To determine who has the greater kinetic energy, we can use the formula for kinetic energy (KE):

\[ KE = \frac{1}{2} m v^2 \]

Where:

  • \( m \) is the mass,
  • \( v \) is the speed.

For the wildlife keeper:

  • Mass (\( m \)) = 60 kg
  • Speed (\( v \)) = 5 m/s

Calculating kinetic energy for the wildlife keeper: \[ KE_{\text{keeper}} = \frac{1}{2} \times 60 , \text{kg} \times (5 , \text{m/s})^2 = \frac{1}{2} \times 60 \times 25 = 750 , \text{J} \]

For the rabbit:

  • Mass (\( m \)) = 4 kg
  • Speed (\( v \)) = 5 m/s

Calculating kinetic energy for the rabbit: \[ KE_{\text{rabbit}} = \frac{1}{2} \times 4 , \text{kg} \times (5 , \text{m/s})^2 = \frac{1}{2} \times 4 \times 25 = 50 , \text{J} \]

Comparing the two kinetic energies:

  • Kinetic energy of the wildlife keeper = 750 J
  • Kinetic energy of the rabbit = 50 J

Since 750 J > 50 J, the wildlife keeper has the greater kinetic energy.

Therefore, the correct response is: The wildlife keeper because they have a greater mass.