As shown below, an object with a mass of 5 kg is moving at a speed of 10 m/s. Another object with a mass of 10 kg is moving at a speed of 5 m/s.

Which of the objects has higher kinetic energy?

(1 point)
Responses

The objects have equal kinetic energy.
The objects have equal kinetic energy.

Both objects have zero kinetic energy.
Both objects have zero kinetic energy.

The 5 kg object has higher kinetic energy.
The 5 kg object has higher kinetic energy.

The 10 kg object has higher kinetic energy.

1 answer

To determine which object has higher kinetic energy, we can use the kinetic energy formula:

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

where \( m \) is the mass of the object and \( v \) is its speed.

For the 5 kg object: \[ KE_1 = \frac{1}{2} \times 5 , \text{kg} \times (10 , \text{m/s})^2 = \frac{1}{2} \times 5 \times 100 = 250 , \text{J} \]

For the 10 kg object: \[ KE_2 = \frac{1}{2} \times 10 , \text{kg} \times (5 , \text{m/s})^2 = \frac{1}{2} \times 10 \times 25 = 125 , \text{J} \]

Now comparing the two kinetic energies:

  • \( KE_1 = 250 , \text{J} \) (for the 5 kg object)
  • \( KE_2 = 125 , \text{J} \) (for the 10 kg object)

The 5 kg object has a higher kinetic energy than the 10 kg object.

Therefore, the correct response is:

The 5 kg object has higher kinetic energy.