Lesson 41: Power
The word power is most often associated with electricity in everyday use, but this is not the case in
physics.
Power is the rate at which work is done.
This means that power measures how quickly energy is being used.
Since it is the ra

Lesson 30: Gravitational Field Strength
In the last lesson we were able to combine our two formulas for force due to gravity to get a new
formula.
Fg=F g
Gmtest Me
mtest g=
2
r
GM
g= 2 e
r
The great news is that the mass (shown above as the mass of the Ea

Physics 20
Chapter 8 Worksheet
Answer the following questions on a separate sheet. Make sure to follow all rules for setting up a question, sig
digs, and scientific notation when appropriate. Answers follow all questions in italics.
1. The engine on a hel

Lesson 11: The Other Formulas
There are several other formulas that are very useful when the acceleration is uniform.
Do not use these equations if the acceleration is changing! The acceleration must be constant.
These other formulas are based on combin

Lesson 21: Free Body Diagrams
We will need a way to organize forces that are acting on a particular object. The easiest way to do this
is by using a free body diagram.
A free body diagram is just a simple sketch of the object showing all the forces that

Adding Vectors in 2 Dimensions
Example to follow
What
is the sum of displacements of
v
vdA 20 m at 15.0 N of E and
dB 28 m at 60 S of E?
Start by drawing the vectors on a
coordinate system, making a scale to
determine length and a protractor to
measure an

Lesson 42b: First Law of Thermodynamics
The First Law of Thermodynamics can be stated in several ways.
The easiest thing to say is that energy can not be created or destroyed, only change form or be
transferred. This is sometimes called the Law of Conserv

Lesson 28: Mass, Weight, & Fields
Newton's work was all related to one goal he had for himself. to explain gravity.
Newton realized that to explain the force due to gravity, he would first have to come up with a
set of rules to explain forces in general.