If a 2 kg mass moves at 3 m/s, what is its kinetic energy?

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Multiple Choice

If a 2 kg mass moves at 3 m/s, what is its kinetic energy?

The main idea here is kinetic energy, which comes from the formula KE = 1/2 m v^2. It tells us energy increases with both the mass and the square of the speed. For a mass of 2 kg moving at 3 m/s, square the speed: v^2 = 3^2 = 9. Then KE = 1/2 × 2 × 9 = 1 × 9 = 9 joules. So the correct value is 9 J. A common slip is forgetting the 1/2 factor, which would give 18 J, not 9 J.

The main idea here is kinetic energy, which comes from the formula KE = 1/2 m v^2. It tells us energy increases with both the mass and the square of the speed.

For a mass of 2 kg moving at 3 m/s, square the speed: v^2 = 3^2 = 9. Then KE = 1/2 × 2 × 9 = 1 × 9 = 9 joules.

So the correct value is 9 J. A common slip is forgetting the 1/2 factor, which would give 18 J, not 9 J.

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