There are four objects being measured for their kinetic energy.

- Object 1 has a mass of 20 kg and a velocity of 4 m/s.

- Object 2 has a mass of 6 kg and a velocity of 10 m/s.

- Object 3 has a mass of 50 kg and a velocity of 2 m/s.

- Object 4 has a mass of 10 kg and a velocity of 5 m/s.

Which of the four objects has the highest amount of kinetic energy?

Object 1

Object 2

Object 3

Object 4

1 answer

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 object.

Object 1:

  • Mass \( m = 20 \) kg
  • Velocity \( v = 4 \) m/s

\[ KE_1 = \frac{1}{2} \times 20 \times (4)^2 = \frac{1}{2} \times 20 \times 16 = 10 \times 16 = 160 , \text{J} \]

Object 2:

  • Mass \( m = 6 \) kg
  • Velocity \( v = 10 \) m/s

\[ KE_2 = \frac{1}{2} \times 6 \times (10)^2 = \frac{1}{2} \times 6 \times 100 = 3 \times 100 = 300 , \text{J} \]

Object 3:

  • Mass \( m = 50 \) kg
  • Velocity \( v = 2 \) m/s

\[ KE_3 = \frac{1}{2} \times 50 \times (2)^2 = \frac{1}{2} \times 50 \times 4 = 25 \times 4 = 100 , \text{J} \]

Object 4:

  • Mass \( m = 10 \) kg
  • Velocity \( v = 5 \) m/s

\[ KE_4 = \frac{1}{2} \times 10 \times (5)^2 = \frac{1}{2} \times 10 \times 25 = 5 \times 25 = 125 , \text{J} \]

Now let's summarize the kinetic energies:

  • \( KE_1 = 160 , \text{J} \)
  • \( KE_2 = 300 , \text{J} \)
  • \( KE_3 = 100 , \text{J} \)
  • \( KE_4 = 125 , \text{J} \)

Conclusion: Object 2 has the highest amount of kinetic energy at 300 J.