# Tatsch Vocab for Final

## 69 terms

### Newton

Law of Universal Gravitation; Unit of Force named after him

### Kepler

found laws of planetary motion

### Hooke

found law of F=kx for springs

### Doppler

found relationship of observed frequency when objects move relative to each other

### work

F x d : F must be parallel to d

### kinetic energy

the energy of motion

stored energy

### elastic potential energy

the energy of stretched or compressed spring

### gravitational potential energy

energy stored in gravitational field

### mechanical energy

the sum of kinetic energy and potential energy; potential or kinetic energy

### power

the rate at which work is done

### conservation of energy

mechanical energy cannot be created or destroyed; it changes form from kinetic to potential and back

### momentum

a quantity defined as the product of the mass and velocity of an object; mass x velocity

### impulse

the product of the force and the time over which the force acts on an object; Ft which is also equal to change in momentum

### conservation of momentum

the total momentum is not changed in collision

### elastic collision

objects bounce off each other; Kinetic energy is conserved

### inelastic collision

objects stick together; kinetic energy is not conserved

### centripetal force

the net force toward the center; force causing change in direction no change in speed

### centripetal acceleration

acceleration directed toward the center

### critical speed

the minimum speed an object can go to get over top of a vertical circle

### Newton's Law of Universal Gravitation

any two masses attract each other depending on how big the masses are and how far they are from each other

### Kepler's law

planets travel in ellipses; velocity of planet is larger when planet is closer to the sun

### Torque

a force that causes the object to rotate; force x lever arm

### lever arm

the perpendicular distance from the force to center of rotation

### moment arm

another name for lever arm

### rotational equilibrium

when net torque is 0; balanced torque; no rotation

### translational equilibrium

balanced forces; when net force is 0; no acceleration

### simple harmonic motion

periodic motion caused by restoring force which is proportional to the displacement from equilibrium

### restoring force

force directed toward equilibrium location

### Hooke's Law

The restoring force is proportional to displacement; F=-kx

### pendulum

consists of a mass called a 'bob' on a fixed string of negligible mass; simple harmonic motion for small angles

### mechanical waves

waves requiring a medium (ex: sound, water, etc.)

### pulse wave

consists of one traveling pulse (non-periodic); one time; single disturbance in medium

### periodic wave

wave whose source is some form of periodic motion; on going; periodic disturbance in medium

### crest

highest point of a wave

### trough

lowest point of a wave

### wave speed

distance a wave pulse travels in a second

### wavelength

distance waves travel in one cycle (or distance from crest to crest)

### frequency

number of waves that pass a given point per second; the number of cycles in a unit of time; how many waves travel across a point each second

### amplitude

maximum displacement of medium from equilibrium

### period

the time it takes for one complete cycle of motion; the amount of time for one wave to pass

### transverse wave

vibrates perpendicular to wave motion

### longitudinal wave

vibrates parallel to wave motion

### constructive interference

crest meets crest and amplitudes are added; when 2 waves at same time and place have combined amplitude less than their original amplitudes

### destructive interference

crest meets trough and amplitudes are subtracted; when 2 waves at same time and place have combined amplitude greater than their original amplitudes

### hertz

measurement of frequency

### natural frequency

the frequency an object vibrates when disturbed

### forced vibration

frequency and object vibrates at when in contact with a vibrating object

### resonance

occurs when the forced vibration matches the object's natural frequency, causing a dramatic increase in amplitude of the wave; when forced frequency is same as natural frequency. Large amplitude results

### pitch

our impression of the frequency of sound either high or low

### intensity

loudness of sound

### relative intensity

how we perceive loudness; measured in decibels

### decibel

measurement of relative intensity; for each 10 decibels increase, intensity increases by a power of 10

### Doppler effect

an observed change in frequency when there is relative motion between the source of waves and an observer; shift in frequency of sound observed due to relative motion of observer and source

### Coulomb

experiments in electricity led him to discover the electric force law . Unit of charge is named after him

### Franklin

named the two different kinds of electric charge positive and negative

### JJ Thompson

discovered the election and determined its charge by finding the smallest charge that could be isolated

### Rutherford

discovered the proton and used particle scattering experiments

discover the neutron

### static electricity

electricity due to not moving charges; created by getting excess electrons or too few electrons "stuck" on an object

### quantized

electrons and protons have a fixed amount of charge called the fundamental charge. the charge occurs as integer multiples of this fundamental charge

### charging by rubbing

friction; creates static electricity; free moving electrons can be "rubbed off" of one object and on to another; when 2 objects are rubbed together one object can give up electrons to the other object, leaving one object positively charged and the other object negatively charged

### charging by contact

when a charged object is touched to a conductor, some of the excess charge will flow onto the conductor leaving it charged

### changing by induction

process of charging a conductor by bringing it near another charged object and grounding the conductor

### polarization

when the positive and negative charges in a molecule shift, resulting in more positives on one side than the other

### conductor

material in which electrons move freely (ex: copper, aluminum, most metals)

### insulator

material in which elections can NOT move freely (glass, silk, plastic, etc)

### semiconductor

only conducts electricity under certain circumstances (ex: silicon)

### electroscope

uses metal leaves suspended on a metal post. When charged the leaves separate since both leaves are charged the same way and they therefore repel each other