What will happen?

https://www.youtube.com/watch?v=1jvr5UPudUk chairs

https://www.youtube.com/watch?v=Z3xyqfCZmSU skateboards

Newton’s 3rd Law of Motion

•For every action, there is an equal and opposite reaction.

What does this mean?

• For every force acting on an object, there is an equal force acting in the opposite direction. • For example: gravity is pulling you

down in your seat, but Newton’s Third Law says your seat is pushing up against you with equal force. • This is why you are not moving.

There is a balanced force acting on you– gravity pulling down, your seat pushing up.

For every action, there is an equal and opposite reaction.

For every action, there is an equal and opposite reaction.

For every action, there is an equal and opposite reaction.

• The baseball applies a force the bat (an action); and the bat applies a force to the ball (the reaction).

For every action, there is an equal and opposite reaction.

https://www.youtube.com/watch?v=EUQAfajlEKs

• A car’s wheels spin, they grip the road and push the road backwards (Action)• The car moves forwards (reaction)

For every action, there is an opposite an equal reaction.

• If I push on a wall, what will happen?• The wall will push back•What if I try to twist a screwdriver?• The screwdriver will twist back. • On earth this is not a problem, my

feet have enough friction to hold me in place.• But in outer space…

https://www.youtube.com/watch?v=PrJnWTcW55s

Physics of Rowing

• A crew team pushes the water backwards to propel the boat forwards.

Review of Newton’s three Laws

• 1st Law: Objects in motion tend to stay in motion and objects at rest tend to stay at rest unless acted upon by an unbalanced force.

• 2nd Law: Force equals mass times acceleration (F = ma).

• 3rd Law: For every action there is an equal and opposite reaction.

Review of Newton’s three laws on a bike

https://www.youtube.com/watch?v=JGO_zDWmkvk

Balloon Car Challenge• Can you use your knowledge of motion

and forces to create a car that will travel 5m in the hallway using a single balloon for power?• Your materials are:• Cardboard• Four plastic lids• Bamboo skewers• Tape • Straws• balloon