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 10 kg object has higher kinetic energy.
The 10 kg object has higher kinetic energy.

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

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

The 5 kg object has higher kinetic energy.

1 answer

To determine which object has higher kinetic energy, we can use the formula for kinetic energy (KE):

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

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

For the 5 kg object moving at a speed of 10 m/s:

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

For the 10 kg object moving at a speed of 5 m/s:

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

Now we compare 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 higher kinetic energy.

So the correct response is: The 5 kg object has higher kinetic energy.