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 wildlife keeper because they have a greater mass.
The wildlife keeper because they have a greater mass.

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

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

Neither one because they are moving at the same speed.

1 answer

To compare the kinetic energy of the wildlife keeper and the rabbit, we can use the formula for kinetic energy:

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

Where \( m \) is the mass and \( v \) is the speed.

Given:

  • Wildlife keeper mass = 60 kg
  • Rabbit mass = 4 kg
  • Speed of both = 5 m/s

Calculating the kinetic energy for both:

  1. Wildlife Keeper's Kinetic Energy: \[ KE_{keeper} = \frac{1}{2} \times 60 , kg \times (5 , m/s)^2 \] \[ KE_{keeper} = \frac{1}{2} \times 60 \times 25 \] \[ KE_{keeper} = \frac{1}{2} \times 1500 \] \[ KE_{keeper} = 750 , J \]

  2. Rabbit's Kinetic Energy: \[ KE_{rabbit} = \frac{1}{2} \times 4 , kg \times (5 , m/s)^2 \] \[ KE_{rabbit} = \frac{1}{2} \times 4 \times 25 \] \[ KE_{rabbit} = \frac{1}{2} \times 100 \] \[ KE_{rabbit} = 50 , J \]

Comparing the two:

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

Conclusion: The wildlife keeper has the greater kinetic energy because they have a greater mass.

The correct response is:

The wildlife keeper because they have a greater mass.