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

Question

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

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

Oa 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

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 the velocity.

For each car, since they all have the same mass (500 kg), we can compare their kinetic energies based on their velocities:

1. Red car: \[ KE = \frac{1}{2} \times 500 , \text{kg} \times (3 , \text{m/s})^2 = \frac{1}{2} \times 500 \times 9 = 2250 , \text{J} \]

2. Blue car: \[ KE = \frac{1}{2} \times 500 , \text{kg} \times (30 , \text{m/s})^2 = \frac{1}{2} \times 500 \times 900 = 225000 , \text{J} \]

3. Green car: \[ KE = \frac{1}{2} \times 500 , \text{kg} \times (21 , \text{m/s})^2 = \frac{1}{2} \times 500 \times 441 = 110250 , \text{J} \]

4. Yellow car: \[ KE = \frac{1}{2} \times 500 , \text{kg} \times (12 , \text{m/s})^2 = \frac{1}{2} \times 500 \times 144 = 36000 , \text{J} \]

Now let's summarize the kinetic energies:

• Red car: 2250 J
• Blue car: 225000 J
• Green car: 110250 J
• Yellow car: 36000 J

The object with the greatest kinetic energy is the blue car, with 225000 J.