Download KE and PE Practice Problems Name Kinetic Energy Definition

KE and PE Practice Problems
Name ________________
Kinetic Energy
Definition: Kinetic Energy (KE) is the energy of an object in motion. The metric unit of KE is
Joules.
1. Calculate KE of a proton of mass 1.67 x 10-27 kg, traveling at 5.2 x 107m/s?
2. What is the kinetic energy of a 3.2 kg pike swimming at 0.5m/s?
3. What is the change in the kinetic energy of a 100kg Kangaroo when it slows down from 3m/s
to 0.5m/s?
4. A 712kg car is traveling at 5.6m/s when a force acts on it for 8.4s, changing its velocity to
10.2m/s. What is the change in the KE of the car?
Potential Energy
(GPE) = m g h
Definition: Gravitational Potential Energy (GPE) is the energy an object has due to its position.
This position is due to gravity (So position change should only be in the vertical direction. The
metric unit of GPE is Joules.
1. What is the Gravitational Potential Energy in a 75kg mass that is lifted 4m?
2. Each step of a ladder increases one’s vertical height by 40cm. If a 90kg painter climbs 8 steps
of the ladder, what is the increase in GPE?
3. A 0.25kg ball is dropped from a height of 3.2m and bounces to a height of 2.4m. What is its
loss in potential energy?
Conservation of Energy (COE):
Name ______________________
The BIG Breakaway Pendulum
Consider the sketch below. Use your knowledge of conservation of energy and kinematics to
solve the problem below. You may use any reference material necessary. You may not consult
with other students or use their reference material. Show ALL work clearly and in an organized
manner in order to earn full credit.
m = 200 g
h = ____________
h = ____________
dy = ____________
Given m, h, and dy ….
Find dx
1. My prediction for efficiency:
2. I predict this efficiency because:
dx = ?
Jumping Frog Lab
1. “Pop” the jumping frog. What kind of energy does the frog have at the top of
the jump?
2. What kind of energy did the frog have at the start of the jump?
3. Remember from your Energy on Shelves Gizmo, that potential energy depends upon
,
, and
.
Potential Energy can be calculated with the following equation:
PE = (mass)(strength of gravity)(height)
4. Measure the mass of your frog:
5. The strength of gravity is:
6. Measure the maximum height of your frog:
7. Calculate the potential energy of your frog:
8. Draw the kind of energy that the frog has
at each point in its travel up and down. (Use
only kinetic and potential. Because there is
really no friction in the air, there is not any
thermal).
9. Roller coasters also have lots of energy transformations. Draw the pie charts for each point
below. Assume there is no friction.
W
X
Y
Z
10. Assume point Y is 100 meters high. How much potential energy does a rider have at point Y,
if her mass is 50 kilograms?
11. How much potential energy does the 50 kilogram rider have if she is at point Z, and is only
50 meters high?
12. How much kinetic energy does she have at point Z?
13. How much potential energy does she have at point W, where she is on the ground and has a
height of 0 meters?
14. How much kinetic energy does she have at point W?