wildlife keeper: 60kg and 5 m/s

rabbit: 4kg and 5 m/s

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.

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

1 answer

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

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

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

  1. For the wildlife keeper:

    • Mass \( m = 60 , \text{kg} \)
    • Velocity \( v = 5 , \text{m/s} \)

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

  2. For the rabbit:

    • Mass \( m = 4 , \text{kg} \)
    • Velocity \( v = 5 , \text{m/s} \)

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

Now, comparing the kinetic energies:

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

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

Correct response: The wildlife keeper because they have a greater mass.