Chapter 4 Flashcards
Speed
How fast an object will go in a specific period of time.
Velocity
The speed and direction of an object.
Acceleration
The change in the velocity of an object, whether in speed or direction.
Momentum
The product of an object’s mass and velocity
Acceleration of gravity
The acceleration of a falling object
Force
Anything that can cause a change in momentum
Net force
The combined effect of all the individual forces acting on an object. If two forces act on an object in opposite directions, the net force would be the remaining force. If two forces act on an object in the same direction, the net force would be the combined amount of both forces.
Angular momentum
Momentum attributable to rotation or revolution. The angular momentum of an object moving in a circle of radius r is the product m x v x r
Torque
The type of force that can change an object’s angular momentum. You can think of this as a twisting force.
Mass
The amount of matter in your body
Weight
The force that a scale weighs when you stand on it. Weight depends both on your mass and on the forces (including gravity) acting on your mass.
Free-fall
Falling without any resistance to slow you down.
Newton’s first law of motion
An object moves at a constant velocity if there is no net force acting upon it.
Newton’s second law of motion
force = mass x acceleration (F = ma) force = rate of change in momentum
Newton’s third law of motion
For any force, there is always an equal and opposite reaction force.
Conservation of momentum
As long as there are no external forces, the total momentum of interacting objects cannot change; that is, 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.
Angular momentum
Angular momentum = m x v x r
Conservation of energy
Energy cannot appear out of nowhere or disappear into nothingness. Objects can gain or lose energy only by exchanging energy with other objects.
Kinetic energy
Energy of motion; The energy of a moving object is 1/2mv2(squared)
Radiative energy
Energy carried by light
Potential energy
Stored energy
Joule
The standard unit of energy;
Thermal energy
The collective kinetic energy of the many individual particles (atoms and molecules) moving randomly within a substance like a rock or the air or the gas within a distant star.
Temperature
The average kinetic energy of the particles
Gravitational potential energy
The potential energy of an object based on its mass and how far it can fall as a result of gravity
Mass-energy
The potential energy of an object based on its mass.
