false

Unlock Document

Physics

PHYS 112

Carey Bissonnette

Winter

Description

PHYS 112 Review
Chapter 13: Oscillations about Equilibrium
Simple Harmonic Motion
- Non constant acceleration
- Periodic motion: motion that repeats itself
- Oscillatory motion: periodic motion that moves back and forth over the same path
Period (T): the time required for a motion to repeat, time required for one cycle of periodic motion
Frequency: the number of oscillations per unit time: f=1/T
Angular Frequency: w = 2πf = 2π/T
Position: x(t)=Acoswt
Velocity: v(t)=-Awsin(wt)
2 2
Acceleration: a(t)=-Aw cos(wt) = -w x(t)
Where A is the amplitude of motion, w is the angular frequency of motion, and f is the frequency of
motion
A linear restoring force will give you simple harmonic motion. The linear restoring force tries to push the
mass back to equilibrium position.
Hooke’s Law: F= -kx = ma
2
KE= ½mv
PE= ½kx 2
Energy doesn’t change when mass is doubled, however, maximum velocity does.
Chapter 14: Waves and Sound
Periodic disturbance – transfer of energy without transferring materials
2 kinds of waves: transverse and longitudinal
Transverse: disturbance is perpendicular to direction of propagation
Longitudinal: disturbance is parallel to direction of propagation
v: velocity of wave (constant for constant medium)
A: amplitude (height of disturbance)
λ: wavelength, repeated disturbance
f: frequency, number of full waves that pass a point
T: period, time for one wavelength to pass a point
v=distance/time=x/T=fλ Superposition principle: 2 waves travelling toward each other meet and pass through each other. Where
the waves overlap you see the sum of the two waves:
constructive interference (waves that give a larger amplitude), in phase, louder noise, r =r +nλ
1 2
destructive interference (waves that give a smaller amplitude), out of phase, quiet noise r1=r2+(n+1/2 )λ
Sound: in solid medium: √
in fluid or gas medium: √
When a sound wave passes from air to water, wave speed must change (different medium). However,
frequency does not change, as it is determined by the source. Now v= fλ, and because f is constant, and
v changed, λ must also change.
Sound source emits energy over time: Power of source –
Sound intensity (power passing through an area):
Intensity level (sound level): , where I0is the threshold of hearing, and β is in decibels.
Standing waves on a String Standing Waves in an Air Column Chapter 19: Electric Charges, Forces, and Fields
Static Electricity: like repels like, opposites attract
Charge on one e = -1.602 x 10 -19C (C = Coulomb)
-31 -27
m e 9.11 x 10 kg m =p1.67 x 10 kg
2
Coulomb’s Law: F = (k*q *q 1/r 2
To solve for the force acting on a charge, just add all the forces acting on the charge:
1. Draw a picture
2. Draw all the force vectors acting on the charge (direction)
3. Calculate magnitude and components of each foce
4. Add them up
| |
Point Charge:
Chapter 20: Electric potential and Electric Potential Energy
Work = W = F*d = F*dcosθ
W=FΔx
W=ΔKE=KE-KE f thii is a conservative force
Uniform Electric Field: F=qE
W=Fd=qEd
Potential Energy
ΔPE = -W = -(qE (xxxf) i (k*q *q)0r
Electric Potential Difference: ΔV=V -V b ΔaE/q = -W/q
ΔV=-Ed
Capacitor: Electrical component used to store energy for a short period of time
Battery: pumps charge and maintains a potential difference across battery
Conductor: electrons free to move – metals binsulator: electrons are tightly bound to atoms – non-metal
Current is the motion of electrons – traditional current involves the positive charges moving
Capacitance: the measure of the ability of a capacitor to store charge: C=Q/V unit: farad, f
Parallel Plate Capacitor:
Dielectrics: a dielectric is an insulating material that increases the capacitance of a capacitor. The
dielectric constant, k, reduces the electric field by a factor of k. the potential difference between capacitor plates is decreased by the factor k.
Chapter 21: Electric current and direct current circuits
Current: I=Q/t unit is Ampere, Amp; 1A=1C/s I=V/R
Electromotive force: emf, ε, is the potential difference between the terminals of a battery under ideal
conditions
Work done by a battery: W=ΔQ*ε
Resistivity: ρ, the resistivity of a material determines how much resistance it gives to the flow of electron
current.
Ohm’s Law: V=I/R
Resistance of a wire: R=ρ(L/A)
Electric Power: P=IV
P=(V )/R = I R
2 2
Power dissipation in a Resistor: P = I *R= V /R
Series Parallel
Capacitance
Resistance
Kirchhoff’s rules
Junction Rule (Charge conservation): the algebraic sum of all currents meeting at a junction must equal
zero. Currents entering the junction are taken to be positive, currents leaving are taken to be negative
Loop Rule (Energy Conservation): the algebraic sum of all potential differences around a closed loop is
zero. The potentia

More
Less
Related notes for PHYS 112

Join OneClass

Access over 10 million pages of study

documents for 1.3 million courses.

Sign up

Join to view

Continue

Continue
OR

By registering, I agree to the
Terms
and
Privacy Policies

Already have an account?
Log in

Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.