Physics/Graphing Notes
Independent or Manipulated Variable--- Is the thing that is changed on purpose in an experiment
Dependent or Responding Variable----Is what you are collecting data on in an experiment. It is not controlled by the person performing the experiment.
Constant---Stays the same.
D—Dependent Variable
R—Responding Variable
Y—Y axis
M I X
M----Manipulated Variable
I---Independent Variable
X---X- Axis
What is a Force? A force is a push or a pull
Two Types of Forces:
Balanced Force---A force that is equal on both sides. Does not change the motion of an object. Will not cause an object to become in motion.
Examples:
A person standing on the floor. the person pushes down on the floor, while the floor pushes back on the person.
A car traveling at a constant speed/velocity. All of the forces are in balance. The car is staying constant. It is not speeding up. Not slowing down. Not changing directions.
Unbalanced Force—When a force is greater on one side of an object than another. Unbalanced forces can cause objects to become in motion, stop, or change directions.
Example:
- Kicking a ball.
- Gravity can be an unbalanced force.
- Friction can be an unbalanced force
Newton’s Laws of Motion
Newton’s 1st Law (Also known as Law of Inertia):
An object in motion will remain in motion or an object at rest will remain at rest, unless an unbalanced force acts upon it.
Example:
A car slamming into a telephone pole. The driver is thrown from the vehicle. This is because the person stays in motion because there is not an unbalanced force to stop them.
Intertia Lab—(Tray/Rocks/Pennies) The tray remains at rest until an unbalanced force (pennies) causes the tray to move.
What is Inertia?
Inertia is the tendency of an object to stay moving in a strait line or to remain at rest. (Inertia means that objects don’t want to change.)
In order to overcome inertia there must be an unbalanced force. Whether the object is starting, stopping, or changing directions inertia must be overcome in order to change the motion of the object.
This is why inertia is newton’s first law of motion.
Newton’s 2nd Law of Motion:
Force = Mass x Acceleration
Example:
It takes more force to move a bus than a smart car, because the bus has more mass than a smart car.
The more mass an object has the more force it can potentially have
The faster the object the more force it can potentially have.
Newton’s 3rd Law of Motion:
For every action there is an opposite and equal reaction.
Example:
- Space shuttle launch (rockets engine pushes air downward, while rocket moves upward)
- Shooting a gun (the bullet is propelled out of the barrel, while the gun recoils and pushes back)
- Rowing a boat.
- Swimming (when you swim you pull water toward your legs while propelling yourself forward.)