Physics 110-110A

Alternating Current

Used in transmission of electricity, “back and forth” motions of elections to motion energy

Direct Current

Used in most household devices, continuous flow

Parallel Current

One or more branching pathways from circuit, most modern homes are wired this way

Series Circuit

A network of objects in a circuit that is in a single line, old fashioned Christmas lights

Generator

Converts mechanical energy into electrical energy

Motor

Converts electrical energy into mechanical energy

Magnetism

The attractive or repulsive interaction between current-carrying wires or electric charges in motion

The motion of electric charges is the source of magnetism

Doppler Effect

The apparent shift in frequency of a source due to the motion of the source or observer is known as this concept?

Wave Length

The distance between any two successive points in a waveform is known as which of the following terms?

Wave Speed Formula

V= f x h

V= Velocity f= frequency w= wave length

Transverse Wave

A wave in which the oscillation is perpendicular to the direction of motion of the wave is this type of wave.

Longitudal Wave

A wave in which the oscillation is parallel to the direction of motion of the wave is this type of wave.

A certain wave has a frequency of 80 Hz and a wavelength of 4.0 mm.  What is the wave speed?

.32

Density Equation

Density = Mass / Volume

As a material changes phase from solid to gas, the density of the material generally changes in what way?

Density decreases

Elasticity

How bouncy or stretchy an object is 

Hooke’s Law

F = – k*x

Conduction

Two objects to have physical contact

Convection

Mixing of liquids and gases

Radiation

Energy that may be transmitted through empty space via electromagnetic waves

Four basic phases of matter

1. Solid
2. Liquid
3. Gas
4. Plasma

The Latent Heat of Fusion

The amount of heat to turn a solid into a liquid 

The Latent Heat of Vaporization

The amount of heat needed to turn a gas into a liquid 

Heat

The energy internal to an object

Temperature

A measure of the internal energy of an object

Work

The change in an object’s kinetic energy

Impulse

A change in momentum or rather a force applied over a time

Potential Energy

Stored energy, regardless of how it is stored (electrically, chemically, etc.)

Formula: PE= mgh

Kinetic Energy

The energy of an object’s external motion.

Formula: KE= 1/2 (mv^2)

Examples:

What is the kinetic energy of a 1500 kg car that has a speed of 10 m/s?

75,000 J

What is the potential energy of an 40 kg person at the top of 120 m tower on Earth?

47,040 J

Centripetal Force

The center-pointing force is responsible for keeping objects travelling along a circular path

Centrifugal Force

A center-fleeing pseudo-force is often given credit for keeping objects undergoing circular motion on their circular path.

What is one way to increase torque without using more force?

A longer level arm

Torque

how a force causes a change in rotational motion

Interactions

-An interaction occurs between 2 and only 2 objects

-An object can have any # of interactions

Force: Push/ Pull

Newtons 1st Law

“A body at rest remains at rest and a body in uniform motion remains in motion unless acted upon by an outside force”

A body’s natural state is one of constant velocity and only changes when affected by a non- zero net force.

DID YOU KNOW…. Your body can detect acceleration but not velocity

Newtons 2nd Law

“The acceleration of an object is directly related to the force applied to the object and inversely related to the mass of the object.”

(Sum of forces = Mass x Acceleration)

F= m x a

Newtons 3rd Law

“action/reaction”

“an applied force by an object is experimented in return by the object applying the force.”

Interactions go both ways!

Free body diagram: represents forces acting ON an object

Mass: Measure of inertia

Weight: Gravitational Force

Law of gravitation

“A gravitational force exists between ANY two objects with mass regardless of their location. The force only weakens over great distances, but never truly vanishes.”

ω –>(Greek lowercase omega symbol)

ω = angular velocity

T = 1/f

Frequency

How many times it goes around in a specific amount of time

Period

Amount of time it takes to complete one rotation

Angular Velocity

Speed at which an object rotates

Centripetal Acceleration

Center-pointing phenomenon that helps maintain circular motion

Projectile motion is a form of motion that moves along a curved path( parabola) caused by gravity.

What is the maximum range for a projectile?

45 degrees

Horizontal and vertical direction have nothing to do with each other when talking about projectile motion. The directions are independent.

Suppose you drop a ball and throw a ball forward from the same height. Which will hit the ground first?

They both will hit the ground at the same time

Horizontal Direction: Constant Velocity

Vertical Velocity: Constantly Changing Velocity

Speed

A scalar quantity that describes ‘how fast or slow’ an object is moving

Distance/ Time = Speed

Velocity

A vector quantity that describes ‘how fast or slow’ in a given direction an object is traveling

Displacement/ Time = Velocity

*The sign tells you what direction you are going*

Examples:

An object travels 20 meters in 5 seconds. What is the objects speed?

20/5 = 4m/s

A dog moves from 20 meters to -40 in 1 minute. What is the dog’s velocity?

-1m/s

A person travels 60 meters in 10 seconds. What is the persons speed?

6m/s