Question

A football player throws a 2kg ball,causing the ball to have a kinetic energy of 1225 J while it’s moving. How fast is the ball going?

Answer 1

Answer: 35m/s

Explanation: The formula for kinetic energy is K=1/2mv^2.

K=1225J

m=2kg

We want to solve for v to find how fast the ball is moving.

1225=1/2 * 2 * v^2

1225 = 2/2 * v^2

1225 = 1 * v^2

1225 = v^2

sqrt1225 = v

35 = v

for the units, J = kg * m^2/s^2, the kg cancels out, sqrt removes the square from m^2/s^2, leaving m/s.