Collisions
Collision type A
When an object in motion hits an object standing still.
To lower peak force.
Friction
Collisions between the surfaces of two objects rubbing against each other.
The videos we watched about sounds were what?
A truck with loud music shaking the windows of a store/ a speaker playing loud music.
Kinetic energy depends on an objects _______ and __________
Speed and mass.
Collision type B
What type of materials work the best as protective devices?
Ones that easily deform and have air pockets.
Air resistance
Collisions between particles in the air and an object moving through the air.
In the speaker video we watched what was the speaker making fly around the room?
Plastic bag
Energy transfers between objects in a system through.
Contact forces/collisions/touching
Collision type C
When two objects in motion hit each other.
The three best performing materials in the collision test videos we watched during class.
Large bubble wrap, small bubble wrap, ear plug foam.
Peak force.
The hardest point of impact in a collision.
What is one example of related phenomena?
Point of elasticity
Which type of collision has the most kinetic energy? A, B, or C?
C.
Why would solid steel be a bad material for a protective devices.
It's too hard/ doesn't deform easily/ no air pockets
These forces are acting on a car driving on the street.
Air resistance AND friction
What is one example of a question we wondered about sound making things move?
Many possible answers.
Slow collision reduce peak force more than fast collisions. True or False?
True.
In every collision there is some deformation. True or False.
Protective materials that are thicker increase peak force. True or False
False
The more kinetic energy an object has the less you have to push against it to change its direction.True or False
False
What is the main question of our new unit?
How can sound make things move.
Tradeoffs
Having to sacrifice one thing for another.