Question

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

The kinetic energy (KE) of an object can be calculated using the formula:

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

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

Let's calculate the kinetic energy for each car:

1. **Blue car**:
- Mass = 500 kg
- Velocity = 30 m/s
- \( KE = \frac{1}{2} \times 500 \times (30^2) = \frac{1}{2} \times 500 \times 900 = 225000 \) Joules

2. **Green car**:
- Mass = 500 kg
- Velocity = 21 m/s
- \( KE = \frac{1}{2} \times 500 \times (21^2) = \frac{1}{2} \times 500 \times 441 = 110250 \) Joules

3. **Yellow car**:
- Mass = 500 kg
- Velocity = 12 m/s
- \( KE = \frac{1}{2} \times 500 \times (12^2) = \frac{1}{2} \times 500 \times 144 = 36000 \) Joules

4. **Red car**:
- Mass = 500 kg
- Velocity = 3 m/s
- \( KE = \frac{1}{2} \times 500 \times (3^2) = \frac{1}{2} \times 500 \times 9 = 1125 \) Joules

Now, comparing the kinetic energies:
- Blue car: 225,000 Joules
- Green car: 110,250 Joules
- Yellow car: 36,000 Joules
- Red car: 1,125 Joules

The object with the greatest kinetic energy is the **blue car** moving at 30 m/s.