By what factor will the kinetic energy change if the speed of the baseball is decreased to 54.8 mi/h? Express your answer as an integer.

The Kinetic Energy is approximately 3 times decreased

Explanation:

A baseball weighs 5.13 oz.

a) What is the kinetic energy, in joules, of this baseball when it is thrown by a major league pitcher at 95. o mi/h?

b) By what factor will the kinetic energy change if the speed of the baseball is decreased to 54.8 mi/h? Express your answer as an integer.

Kinetic Energy (KE) = 0.5*mass*velocity ^ 2

Kinetic Energy (KE) = 0.5*mass * velocity ^ 2

Joules = kg*m^2/s^2

1 mile = 1609.344 meters

1 hour = 3600 sec

1 Oz = 28.34952 g = 0.02834952 kg

a) KE=0.5*m*v^2

=0.5 * (5.13 oz * 0.02834952 kg/1 ounce) * (95 miles/h * 1609.344 m/1 mile * 1 hr/3600 s) ^2

=130.761 kg*m^2/s^2 = 130.761 Joules

b) KE=0.5*m*v^2

=0.5 * (5.13 oz * 0.02834952 kg/1 ounce) * (54.8 miles/h * 1609.344 m/1 mile * 1 hr/3600 s) ^2

=43.51028 kg*m^2/s^2 = 43.51028 Joules

= 130.761 / 43.51028 = 3.00528,

As such the Kinetic Energy is approximately 3 times decreased