Day 4: 1st Law

FQ:  How does Newton's First Law relate inertia to forces?

1. Watch about N1L

Learn about Newton's 1st Law of Motion in this video: 

Want to see how Newton's 1st Law applies to football players? Watch here. 

Want to see how Newton's 1st Law applies to car crashes?  Watch here.

Want a song about Newton's 1st Law?  Watch here.

Want to know why inertia is the same thing as "laziness"?  Watch here.

2. Read about N1L

Newton’s 1st Law of Motion: An object at rest will stay at rest, and an object in motion will stay in motion UNLESS acted on by an unbalanced force

• In other words: an object will keep doing what it’s doing until a force changes its motion

If an object is not accelerating (= moving at constant velocity, which COULD be zero), either:

1. no forces are acting on it, or
2. all the forces on it are balanced (they have equal sizes but opposite directions)

3.  Intro:  Friction

Friction is the force that opposes motion.

○Sliding friction – opposes the motion of 2 surfaces as they slide against each other

○Static friction – prevents 2 surfaces from sliding against each other at all

○Rolling friction – static friction keeps a wheel from spinning in place and makes it turn instead

○Fluid friction – friction from liquids and gases

• Air resistance is a force that opposes the motion of objects that move through air
• Air resistance depends on an object’s size, shape, and speed

Group activity:  Classify the 4 types of friction

4. Mini-Lab:  Friction

Complete the following investigation to help you understand how friction affects the motion of objects.

Click this link: https://phet.colorado.edu/sims/html/forces-and-motion-basics/latest/forces-and-motion-basics_en.html 

Next, click the FRICTION image: 

Click "Friction" again. The screen should look like this:

Get Started

Click "take the quiz" to start!

5.  Project:  Answer question #5 about friction in your sport.