# Forces

Newton Schmewton (Forces Pretest)

Newton Schmewton (Forces Pretest) Key
Check the key for the following errors:
5.  the best answer is (c), but it would be even better if it read “the force pressing the two surfaces together”
6.  the answer should be 3.53 x 10^22 N.  (c) is closest.
12.  should refer back to question #11, not #14.
31.(a) the answer should be 5.4 not 5.5 (to two SF)

Random forces notes probably not from your class, and probably incomplete. Hey, I’m trying!

Forces Unit Key Concepts (Good for reviewing! Know all of this!)

Learning Outcomes (these are the things the Government says you should know (I agree btw))

Extra Practice Problems KEY

Dynamics DyProblems for Dymarks. Problem Assignment.  KEY

## Newton’s Laws of Motion

First Law: The Law of Inertia

A video from the European Space Agency

Second Law: Force, Mass and Acceleration

More from the European Space Agency

Third Law: The Action / Reaction Law

Yup, part 3 from the European Space Agency

## Types of Force

#### Gravity

Here is a neat little plug-in from Wolfram Alpha that will calculate the gravitational field strength, g. Try it out!

Try comparing Mt. Kilimanjaro to Baffin Island for example. Which is larger? By how much? Why?

The Kilogram is About to be Redefined and here is one way it’s being tested using the World’s Roundest Object. And they’re getting closer.

How Cavendish measured the force of gravity

Newton’s L.O.U.G.ie (KEY)

Gravitation Got You Down? Worksheet Solutions

#### Friction

Physicist shoots himself underwater. Check out the high friction force!

Here is the Crash Course on sliding friction. Careful, the second half gets into a 2-D problem which is what we do in Physics 12.

Bill Nye on Friction

Dynamics (Forces) Learning Outcomes