1. A
2-kg bowling ball sits on top of a building that is 40 meters tall.
Circle one: KE / GPE / both Show your work for finding the values of
each type of energy the object has:
KE = 0 (because velocity is 0)
PE = mgh = 2kg9.8m/s^240m= 784 joule
- A 2-kg bowling ball rolls at a speed of 5 m/s on the roof of the
building that is 40 tall. Circle one: KE / GPE / both Show your work for
finding the values of each type of energy the object has:
Both
KE = [1/2]mv^2 = [1/2](2kg)(5m/s)^2 = 25 joul
PE = mgh = 40 joule
- A 2-kg bowling ball rolls at a speed of 10 m/s on the ground. Circle
one: KE / GPE / both Show your work for finding the values of each type
of energy the object has:
KE = [1/2]m(v^2) = [1/2]2kg(10m/s)^2 = 100 joule
GPE = mgh = 0
- A 1,000-kg car has 50,000 joules of kinetic energy. What is its speed?
KE = [1/2]m(v^2) => v = √[2KE/m] = √[250,000joules/1000kg] = 10m/s
- A 200-kg boulder has 39,200 joules of gravitational potential energy. What height is it at?
GPE = mgh => h = GPE / (mg) = 39,200 joules / (200kg 9.8m/s^2) = 20m
- A 1-kg model airplane has 12.5 joules of kinetic energy and 98 joules
of gravitational potential energy. What is its speed? What is its
height?
KE = [1/2]m(v^2) => v = √ [ 2KE/m] = √[212.5 j / 1kg] = 7.9 m/s
GPE = mgh => h = GPE/(mg) = 98/(1kg9.8m/s^2) = 10 m
