8. A 60 kg runner has 1500 J of kinetic energy. How fast is he moving?

Answer: 7.07 m/s

Explanation:

Mass of runner = 60 kg runner

Kinetic energy = 1500J

Speed of runner = ?

Recall that kinetic energy is the energy possessed by a moving object, and it depends on its mass and speed by which it moves.

Hence, K. E = 1/2 x mass x (speed) ^2

1500J = 1/2 x 60kg x (speed) ^2

1500J = 30kg x (speed) ^2

(speed) ^2 = 1500J/30kg

(speed) ^2 = 50

To get the value of speed, find the square root of 50

speed = √50

speed = 7.07 m/s

Thus, the runner moves as fast as 7.07 m/s