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)

1 answer

Kinetic energy is calculated using the formula:

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

where \( m \) is the mass and \( v \) is the velocity.

For the wildlife keeper (mass = 60 kg, speed = 5 m/s):

\[ KE_{keeper} = \frac{1}{2} \times 60 , \text{kg} \times (5 , \text{m/s})^2 \] \[ KE_{keeper} = \frac{1}{2} \times 60 \times 25 \] \[ KE_{keeper} = \frac{1}{2} \times 1500 \] \[ KE_{keeper} = 750 , \text{Joules} \]

For the rabbit (mass = 4 kg, speed = 5 m/s):

\[ KE_{rabbit} = \frac{1}{2} \times 4 , \text{kg} \times (5 , \text{m/s})^2 \] \[ KE_{rabbit} = \frac{1}{2} \times 4 \times 25 \] \[ KE_{rabbit} = \frac{1}{2} \times 100 \] \[ KE_{rabbit} = 50 , \text{Joules} \]

Comparing the two kinetic energies:

  • Kinetic energy of the wildlife keeper: 750 Joules
  • Kinetic energy of the rabbit: 50 Joules

Therefore, the wildlife keeper has the greater kinetic energy.