elastic and inelastic

Elastic collision is when two things bounce back off of each other and inelastic is when two things dont bounce off of each ither because they have the same mass. One elastic collision is when you have a small guy bounce off a big guy. One inelastic collision is when two things with the same mass bump into each other.

elastic collisions

A skateboard because it is moving and it has move work and power because it is in motion which
makes it have more momentum.

work vs power

Work is a applied force and power is the rate in which work is being done. One example of more power is when you run up the stairs and one example of less power is when you walk up the stairs.

Mass and Newtons first law

  One example is when there is a car moving and it pushes into a wall because something is stopping the car. Another example is when you have a small guy running into a big guy because something is stopping it from going. Last example is when you have a ball thrown and the ball is stopped by someones hand. The amount of mass affects this though because the more mass something has the faster it stops and the harder is is to stop.

Inertia Investigation

I see inertia when you have a cup, a coin and a index card and you try to get the coin in the cup by moving the index card. Also when you are running and you drop a ball and try to make it land on the x while running. Also when you have 5 poker chips and hit the bottom one and see what happens. One example of things that don't stop moving are clouds because there is nothing in the air to really stop them. One example of one thing moving and the other staying still is when you have two cars and they push in to each other because one car has a larger force and there is more mass on that one car.

Mu-friction

Friction happens because you rub things together and there is energy. Friction also happens because two different types of energy's are meeting each other and are making bad things happen. I think grass or wood would have a greater amount of friction because there is more energy in those two things. 

balanced and unbalanced

Reference https://www.physicsforums.com/threads/drawing-free-body-diagrams.458441/

These are two free body diagrams the picture is balanced and the link is not. You know if they are balanced because the lines are the same length or they are the same numbers. But you can tell if they are unbalanced if the lines are uneven or they have different numbers.