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.

Question

Which of the objects has higher kinetic energy?

(1 point)
Responses

The 5 kg object has higher kinetic energy.
The 5 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 10 kg object has higher kinetic energy.
The 10 kg object has higher kinetic energy.

Answer 1

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

$$KE=\frac{1}{2}m{v}^2$$

where $m$ is the mass of the object and $v$ is its speed.

Let's calculate the kinetic energy for both objects:

1. For the 5 kg object moving at 10 m/s:

$$K{E}_1=\frac{1}{2}\times 5,\text{kg}\times (10,\text{m/s}{)}^2$$ $$K{E}_1=\frac{1}{2}\times 5\times 100=\frac{500}{2}=250,\text{J}$$

2. For the 10 kg object moving at 5 m/s:

$$K{E}_2=\frac{1}{2}\times 10,\text{kg}\times (5,\text{m/s}{)}^2$$ $$K{E}_2=\frac{1}{2}\times 10\times 25=\frac{250}{2}=125,\text{J}$$

Now we can compare the kinetic energies:

• The 5 kg object has a kinetic energy of 250 J.
• The 10 kg object has a kinetic energy of 125 J.

Thus, the 5 kg object has higher kinetic energy.

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