Speed
How far an object will go in a certain amount of time (m/h)
Velocity
both speed and direction (m/h due north)
Acceleration
Change in velocity
Acceleration of gravity
Acceleration of a falling object (g) (9.8)
Momentum
Product of its mass and velocity. Momentum = mass x velocity
Force
The way to change an objects momentum
Angular momentum
Circling momentum, any object that is spinning or moving along a curved path has angular momentum. = (m x v x r)
Mass
Amount of matter in your body
Weight
the force that a scale measure when you stand on it, weight depends on both mass and force
Torque
The type of force that can change an objects angular momentum
Net force
Overall force, the combined effect of all the individual forces put together.
Free-fall
falling without any resistance to slow you down
Weightless
when fee fall causes you to have no weight
Newton's First Law
An object moves at constant velocity if there is no net force acting upon it.
Newton's Second Law
Force = Mass x Acceleration (F= ma)
Newton's Third Law
For any force, there is always an equal and opposite reaction force.
Conservation of momentum
the total momentum of interacting objects cannot change as long as no external force is acting on them, their total momentum is conserved.
Conservation of angular momentum
As long as there is no external torque, the total angular momentum of a set of interacting objects cannot change. An individual object can only change its angular momentum by transferring some angular momentum to or from another object.
Conservation of energy
energy cannot appear out of nowhere or disappear into nothingness. Objects can jain or lose energy only by exchanging energy with other objects.
Kinetic Energy
Energy of motion. (1/2 mv^2)
Radiative Energy
Energy carried by light.
Potential Energy
Stored Energy, which can later be converted into kinetic or radiative energy.
Joule
The standard unit of energy
Thermal Energy
Most important subcategory of kinetic energy. the collective kinetic energy of the many individual particles moving randomly within a substance.
temperature
the average kinetic energy of the particles.
Kelvin temperature scale
Scale used to measures temperature in science. Never uses negative temperatures. Coldest is 0 K
Gravitational Potential Energy
depends on an objects mass and how far it can fall as a result of gravity. An object has more GPE when it is higher and less when it is lower.
mass- energy
second form of potential energy- the energy contained in mass itself.
universal law of gravitation (Newton)
- Every mass attracts every other mass through the force called gravity
- The strength of the gravitational force attracting any two objects is directly proportional to the product of their masses.
- The strength of gravity between two objects decreases w
inverse square law
doubling a distance between two objects weakens the force of gravity by a factor of 2^2 or 4.
Gravitational constant
G = 6.67 x 10 ^-11
Bound orbits
Orbits in which an object goes around another object over and over again.
Unbound orbits
paths that bring an object close to another object just once.
Center of mass
the point at which two objects would balance if they were somehow connected
Newton's version of Kepler's third law
Allows us to measure orbital period and distance in units which we wish.
Gravitational encounter
one way in which two objects can exchange orbital energy. they pass near enough so that each can feel the effect of the other's gravity.
tidal force
A difference in attraction that creates a "stretching force" that stretches the entire Earth to create two tidal bulges, one facing the moon and one opposite the moon
tidal friction
When tidal forces stretch Earth itself, the process creates friction.
Synchronous rotation
the moon always shows the same face to Earth