# Conceptual Physics Vocab (Semester 2)

## 41 terms

### Momentum

the quantity mass times velocity

### (kg)(m/s)

unit for momentum

### Impulse

the quantity force times time which is equal to the change in momentum

### Law of Momentum Conservation

in a closed system, momentum cannot be destroyed or created; the sum of momentum in the beginning is the sum of momentum in the end

### Work

the amount of energy transferred by a force

units of work

### Power

the rate at which work is done

unit of power

### Potential energy

the stored energy of an object's position

### Kinetic energy

an object's energy of motion

### Mechanical Energy

the result of an object's motion and/or its stored energy of position

### Conservative or Internal Force

Type of force that will not change the total mechanical energy of object

### Non-Conservative or External Force

Type of force that will change the total mechanical energy of object

### Vector

a quantity with magnitude and direction

### Scalar

a quantity with magnitude

### Gravitational constant

the constant gravitational force in the universe

### Law of Universal Gravitation

every object in the universe attracts every other object with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them

### Centripetal force

a force that makes a body follow a curved path

### Weightlessness

feeling when normal force is less than the force of gravity; not possible because mass and gravity are always present

### Newton's First Law

An object at rest tends to stay at rest and an object in motion tends to stay in motion unless acted upon by an unbalanced force

### Newton's Second Law

the acceleration of an object is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object

### Newton's Third Law

The mutual forces of action and reaction between two bodies are equal and opposite

### Acceleration vector

vector that always points toward the center of the circle

### Velocity vector

vector that always points tangent to the circle

### Gravity

the means by which objects with mass attract one another

### Inverse-Square Law

the gravitational attraction force between two masses is directly proportional to the product of their masses and inversely proportional to the square of their separation distance

### Buoyancy

an upward acting force, caused by fluid pressure, that keeps things afloat

### Conduction

the transfer of thermal energy through matter

### Convection

the movement of heat within fluids

energy that travels through space and ultimately is absorbed

### Insulator

a material used to resist the flow of heat

### Fluids

both gases and liquids

### Heat capacity

the quantity of heat required to raise the temperature of a unit mass of the substance by 1 degree

### Heat

measure of substance's internal energy

### Temperature

the quantity that tell how hot or cold something is compared with a standard

### Thermal energy

total kinetic energy (due to the motion of particles) and potential energy

### Internal energy

The total kinetic and potential energy from the motions and relative positions of the molecules of an object

### Thermal contact

the exchange of energy through the process of heat

### Thermal equilibrium

when thermal contact between two objects reach the same temperature, and heat discontinues to flow between them

### calorie

the amount of heat required to raise the temperature of 1 gram of water by 1⁰ C

### Newton's Law of Cooling

the rate of heat loss in an object is proportional to the difference in temperatures between the object and its surroundings