Question

Question
Which object has the greatest kinetic energy?(1 point)
Responses

a green car with a mass of 500kg moving at 21 m/s
a green car with a mass of 500kg moving at 21 m/s

a blue car with a mass of 500 kg moving at 30 m/s
a blue car with a mass of 500 kg moving at 30 m/s

a yellow car with a mass of 500 kg moving at 12 m/s
a yellow car with a mass of 500 kg moving at 12 m/s

a red car mass of 500 kg moving at 3 m/s
a red car mass of 500 kg moving at 3 m/s

Answer 1

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

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

where:
- \( KE \) is the kinetic energy,
- \( m \) is the mass of the object,
- \( v \) is the velocity of the object.

Since all the cars have the same mass of 500 kg, we can compare their kinetic energies by calculating \( v^2 \) for each car.

1. **Green Car**:
- \( v = 21 \, \text{m/s} \)
- \( v^2 = 21^2 = 441 \)

2. **Blue Car**:
- \( v = 30 \, \text{m/s} \)
- \( v^2 = 30^2 = 900 \)

3. **Yellow Car**:
- \( v = 12 \, \text{m/s} \)
- \( v^2 = 12^2 = 144 \)

4. **Red Car**:
- \( v = 3 \, \text{m/s} \)
- \( v^2 = 3^2 = 9 \)

Now we can summarize the \( v^2 \) values:
- Green Car: 441
- Blue Car: 900
- Yellow Car: 144
- Red Car: 9

The blue car has the highest \( v^2 \) value (900), which means it has the greatest kinetic energy.

So, the answer is:
**a blue car with a mass of 500 kg moving at 30 m/s**.