how to do Kinetic Energy?

Question

The goose has a mass of 24.4lbs and is flying at 9.00 (miles per hour). What is the kinetic energy of the goose?

Answer 1

First, let's clarify something: lbs are not a unit for mass. lbs are the units of force or weight (W), which is a kind of force. In the English system of measure, slugs are the units for mass. 1 slug = 32.2 lbs/32.2 ft/sec^2 when we solve for mass m = W/g and g = 32.2 ft/sec^2 on Earth's surface.

That being said, we have kinetic energy KE = 1/2 mv^2; where v = 9 mph = 13 fps, and m = W/g = 24 lbs/32.2 ft/sec^2 ~ .8 slugs. Thus we have KE = 1/2 .8 (169) ~ 68 slug (ft/sec)^2 or 68 foot-pounds. Note a slug-ft/sec^2 = pound.

Bottom line, ensure you understand the difference between force (like weight) and mass.

Answer 2

just apply the formula
Ec= 1/2 mV^2

Ec= kinetic energy
m=mass
V= speed