IPC Final Exam

velocity

speed and direction object is moving

when adding two or more velocities

use vector addition

a vector

quantity with size and direction

force

push or pull that acts on an object

true or false: a force can cause a resting object to move

true

A force can accelerate a moving object by changing the object’s

speed or direction

net force

overall force acting on an object after all the forces are combined

balanced forced have a net force of

zero

an object accelerates when

an unbalanced force acts on it

friction

force that oppeses the motion of objects that touch as they move past each other

static friction

acts on objects that aren’t moving

static always acts in the direction…

opposite to the direction of the applied force

sliding friction

force that opposes direction of motion of object, as it slides over a surface

sliding friction takes ____ force to keep an object moving than to start it moving

less

rolling friction

acts on rolling objects

fluid friction

opposes motion of an object through a fluid

terminal velocity

constant velocity of a falling object when the force of air resistance equals the force of gravity

work

product of force and distance

work is done

when a force acts on an object in the direction the object moves

for a force to do work, some of that force must

act in the same direction as the object is moving

work formula

work = force x distance

power

rate of doing work

the faster you do work

the more power you need

Power formula

Power = work/time

energy

ability to do work

when work is done on an object, energy…

is transferred to that object

work is a transfer

of energy

energy is usually measured in

joules

kinetic energy of any moving object depends upon its

mass and speed

KE formula

KE = ½ mv²

Potential energy

energy stored as result of position or shape

gravitational potential energy

PE that depends on an objects height

gravitational PE increases

when an object is raised to a higher height

an object’s gravitational PE depends on

its mass, height, and acceleration due to gravity

PE =

mgh or mass x acceleration due to gravity x height

acceleration due to gravity on earth

9.8 m/s²

mechanical wave

disturbance in matter that carries energy from one place to another

medium

material through which a wave travels

solids, liquids, and gases all can act as

mediums

You got this! Almost done!

uggg

a mechanical wave is created when a source of energy…

causes a vibration to travel through a medium

crest

highest point of a wave above the rest position

trough

lowest point below the rest position

transverse wave

wave that causes the medium to vibrate at right angles to the direction in which the wave travels

example of a transverse wave

shaking crumbs off a picnic blanket

compression

area where the particles in a medium are spaced close together

rarefaction

area where particles in a medium are spread out

longitudinal wave

wave in which the vibration of the medium is parallel to the direction the wave travels

example of longitudinal wave

a spring

surface wave

wave that travels along a surface separating two media

periodic motion

any motion that repeats itself at regular intervals

period

time required for one cycle (complete motion that returns to its starting point

frequency

number of complete cycles in given time

hertz (Hz)

cycles per second

wavelength

distance between point on one wave and same point on next wave cycle

increasing frequency

decreases wavelength

wave speed formula

Speed = wavelength x frequency

when the wavelength is in meters and frequency in hertz, the units for speed are

meters per sec

reflection

when a wave bounces off a surface it cannot pass through

reflection does not change the ____ or ____ of a wave, but the wave can be flipped upside down

speed or frequency

refraction

bending of a wave as it enters a new medium at an angle

refraction occurs because

one side of the wave moves more slowly than the other side

diffraction

bending of a wave as it moves around an obstacle or through a narrow opening

interference

when two or more waves overlap and combine

constructive interference

when two or more waves combine to produce a wave with larger displacement

destructive interference

when two or more waves combine to produce a wave with smaller displacements

antinode

point where a crest or trough occurs midway between two nodes

electromagnetic waves

transverse waves consisting of changing electric an magnetic fields

electric field

exerts forces on charged particles

electric fields are produced by

electrically charged particles and by changing magnetic fields

magnetic field

produces magnetic forces

magnetic fields are produced by

magnets, changing electric fields, and by vibrating charges

electromagnetic waves can travel through

a vacuum, an empty space, or matter

electromagnetic radiation

transfer of energy by electromagnetic waves traveling though matter or across space

speed of light in a vacuum

3.00 × 10^8 meters per sec

in a vacuum, all electromagnetic waves travel

at the same speed

the speed of an electromagnetic wave is the product of

its wavelength and frequency

photoelectric effect

emission of electrons from a metal caused by light striking metal

photons

packets of electromagnetic energy

amplitude modulation

wave amplitude is varied (used by AM radio stations)

frequency modulation

the frequency is modulated (used by FM radio stations)

infrared rays

used as source of heat and to discover areas of heat differences

infrared rays

1 mm to 750 nanometers

thermograms

color coded pictures that show variations in pictures

visible light

light visible by the human eye

you cannot see infrared rays, but you can

feel them

ultraviolet rays

has higher frequencies than violet light, wavelengths of 400 to 4 nanometers

X-rays

short wavelengths, 12 to 0.005 nanometers. High energy and can penetrate matter that light cannot

gamma rays

shortest wavelengths in electromagnetic spectrum, 0.005 nanometers or less. Highest frequencies and the most energy.

over exposure to gamma rays can be

deadly

gamma rays are used to

kill cancer cells

objects can be made out of

transparent, translucent, or opaque materials

translucent materials

scatter light (frosted glass, etc.)

transparent materials

transmit light (most of the light which hits it passes through it)

opaque materials

either absorbs or reflects all light that strikes it, no light can pass through it

image

copy of an object formed by reflected or refracted waves of light

regular reflection

occurs when parallel light waves strike a surface and reflect all in the same direction

diffuse reflection

occurs when parallel light waves strike a rough uneven surface, and reflect in many different directions

example of refraction

when light travels from air into water, the straw looks like it has been cut in half

mirage

false or distorted image