Physical Science Midterm

Temperature

Measure of average kinetic energy of particles in a substance

Heat

Transfer of energy between objects due to temperature difference

Specific Heat

Amount of heat energy required to raise the temperature of a substance

Conduction

Transfer of heat through direct contact between particles

Convection

Transfer of heat through the movement of fluid or gas

Radiation

Transfer of heat through electromagnetic waves

Speed

Rate at which an object covers distance

Velocity

Speed in a given direction

Acceleration

Rate of change of velocity

Formula to find speed

Speed = Distance / Time

Formula to find acceleration

Acceleration = Change in Velocity / Time

Work

Measure of energy transfer when a force is applied over a distance

Power

Rate at which work is done or energy is transferred

Absolute Zero

The lowest possible temperature, at which all molecular motion ceases

Formulas for converting between Fahrenheit, Celsius, and Kelvin

Fahrenheit to Celsius: C = (F - 32) * 5/9

Celsius to Kelvin: K = C + 273.15

Fahrenheit to Kelvin: K = (F + 459.67) * 5/9

motion

An object's change in position relative to a reference point.

frame of reference

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

Displacment

the direct change in position of an object

distance

the total distance covered

scaler

Magnitude (size or distance) alone

vector

A quantity that has magnitude and direction

speed

the distance traveled divided by the time interval during which the motion occurred

velocity

the speed of an object in a particular direction

combined velocities

determine the resultant velocity

constant speed

equal distances in equal amounts of time

instantaneous speed

the speed at a given time

acceleration

the rate at which velocity changes over time

positive acceleration

an increase in velocity

negative acceleration

deceleration

inertia

The tendency of an object to resist a change in motion

mass

A measure of the amount of matter in an object

weight

the gravitational force exerted on an object

Newtons first law

Law of Inertia

the more mass you have

the more inertia you have

Newton's second law

Force equals mass times acceleration

Gravity (unless told otherwise)

9.8

Why do objects fall to the ground when dropped?

gravity

What is the relationship between free fall acceleration and mass?

Objects fall at the same rate regardless of their mass

Formula to find momentum

p=mv

What is the total momentum after objects collide?

the same as it was before the collision

Newtons law of universal gravitation

gives the size of the gravitational force between two objects

Free fall

the MOVEMENT of a body when only the force of gravity is on the object

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

momentum

The product of an object's mass and velocity

Formula for the law of universal gravitation

F = G m1m2/d2

Gravitation force increases as

mass increases

Gravitational force decreases as

distance increases

Newton's third law

Action and reaction forces

Newton's Law of Conservation of Momentum

For any closed mechanical system, energy and therefore, momentum are conserved. m1V1=m2V2

Mechanical Advantage

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

MA has....

no unit!

Mechanical advantage (force)

output /input

Mechanical advantage (distance)

input /output

energy

the ability to do work

potential energy

the energy an object has because of it's position, shape, or condition.

PE=mgh

Formula for calculating gravitational potential energy

KE=1/2mv squared

formula for kinetic energy

Kinetic depends on ..... more than mass because it's squared

velocity

nonmechanical energy

energy that lies at the level of the atom

mechanical energy

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

kinetic energy

the energy an object has due to its motion

As potential energy decreases....

kinetic energy increases

Law of Conservation of Energy

Energy can't be created or destroyed

Efficiency

a quantity, usually expressed as a percentage, that measures the ratio of useful work output to work input

Efficiency formula

Work output/work input x 100%

Boiling point for Fahrenheit

212 degrees

Boiling point for Celsius

100 degrees

Freezing point of water in Fahrenheit

32 degrees

Freezing point of water in Celsius

0 degrees

temperature changes indicate.....

an energy transfer

conduction

The direct transfer of heat from one substance to another substance that it is touching.

convection current

a current caused by the rising of heated fluid and sinking of cooled fluid

Formula to find Specific heat

energy=mass times specific heat times change in temp