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A 70 Kg man on a 10 kg bike has 1440 J of kinetic energy. How fast is the
man moving?

1 Answer

10 votes

9514 1404 393

Answer:

6 m/s

Explanation:

The formula for kinetic energy is ...

KE = (1/2)mv² . . . . m is mass

Filling in the given values, we can solve for v.

1440 J = (1/2)(70+10 kg)v^2

(1440 J)/(40 kg) = v^2 = 36 m²/s² . . . . m is meters

v = √(36) m/s = 6 m/s

The man is moving at 6 meters per second.

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In terms of units analysis, the joule (J) is a derived unit equal to ...

1 J = 1 kg·m²/s²

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