Physical Science - Exam Review

Frame of Reference

a system for specifying the precise location of objects in space and time

Motion

an object's change in position relative to a reference point

distance

measures the path taken (total)

displacement

measures the change in position (includes direction)

speed

how fast an object moves (scaler)

velocity

both the speed and the direction an object moves (vector)

calculating speed

distance/time

calculating velocity

displacement/time

speed graph

distance vs. time

Instantaneous Speed

speed at a given time and position

Slope (Speed)

change in distance/change in time

acceleration

the rate at which velocity changes over time

speeds up, slows down, changes direction

acceleration is when an object _ (3 things)

acceleration =

change in velocity/time

centripetal acceleration

The acceleration that occurs in a circular motion is known as _. (2 words)

average acceleration =

final velocity-initial velocity/time

acceleration graph

speed vs. time

Newton's First Law

objects change their state of motion only when a net force is applied

Net force

total amount of force

mass

Inertia is related to an object's _.

Inertia

the tendency of an object to resist a change in motion unless an outside force acts on the object

Newton's Second Law

Net force is equal to mass times acceleration. The unbalanced force on an object determines how much an object speeds up or slows down.

F =

ma

W =

mg

Weight

a measure of the gravitational force exerted on an objects

Fg =

G (m1*m2/d squared)

Free fall

the motion of a body when only the force of gravity is acting on the body

Terminal Velocity

the constant velocity of a falling object when the force of air resistance is equal in magnitude and opposite in direction to the force of gravity

Projectile Motion

the curved path that an object follows when thrown, launched, or otherwise projected near the surface of Earth

horizontal & vertical

Projectile motion has two components --

Newton's Third Law

For every action, there's an equal and opposite reaction

Momentum (p) =

m*v

Momentum

quantity defined as the product of the mass & velocity of an object

kg * m/s

Unit for momentum

Law of Conservation of Momentum

The total momentum of two or more objects after a collision is the same as it was before the collision.

Conservation of Momentum Formula

(m1v1) + (m2v2) = (m1bv1b) + (m2bv2b)

Work

the transfer of energy to an object by the application of a force that causes the object to move in the direction of the force

Work =

f*d

Joules

units for work

Power

the rate at which word is done, or how much work si done in a given amount of time

Power =

work/time

Watts

unit for power

Mechanical Advantage

a quantity that expresses how much a machine multiplies force or distance

Mechanical Advantage =

output force/input force; input distance/output distance

Lever & Inclined Plane

Two families of simple machines: & _

Lever family

simple lever, pulley, wheel & axle

Inclined Plane family

simple inclined plane (ramp), wedge, screw

energy

the capacity to do work

joules

unit for energy

Potential energy

the energy that an object has because of the position, shape, or condition of the object

elastic potential energy

Any object that is stretched or compressed to increase or decrease the distance between its parts has .

gravitational potential energy

Any system of two or more objects separated by a vertical distance has ___.

Grav. PE =

mgh

Kinetic energy

the energy of an object due to the object's motion

KE =

m/2 * v squared

Law of Conservation of Energy

Energy cannot be created or destroyed. The total amount of energy in the world never changes, although energy may change from one form to another.

mechanical energy

the amount of work an object can do because of the object's kinetic & potential energies

temperature

a measure of how hot (or cold) something is

thermometer

an instrument that measures and indicates temperature

Fahrenheit, Celsius, & Kelvin

The three main temperature scales:

Fahrenheit Boiling Temp.

212 degrees F

Fahrenheit Freezing Temp.

32 degrees F

Celsius Boiling Temp.

100 degrees C

Celsius Freezing Temp.

0 degrees C

Celsius to Fahrenheit Formula

1.8 * Tc + 32

Fahrenheit to Celsius Formula

Tf - 32/1.8

Celsius to Kelvin Formula

Tc + 273

Kelvin to Celsius Formula

Tk - 273

Absolute Zero

the temperature at which molecular energy is at a minimum

Heat

the energy transferred between objects that are at different temperatures

Conduction, Convection, & Radiation

What are the three ways that energy transfers?

thermal conduction

the transfer of energy as heat through a material

convection

the movement of matter due to differences in density that are caused by temperature variations

convection current

any movement of matter that results from differences in density; may be vertical, circular, or cyclical

radiation

the energy that is transferred as electromagnetic waves, such as visible light and infrared waves

conductor

a material through which energy can be easily transferred as heat

insulator

a material that transfers energy poorly

specific heat

the quantity of heat required to raise a unit mass of homogenous material 1K or 1*C in a specified way given constant pressure and volume

energy = mcAt

specific heat equation