Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
LPH 105 W15 11:intro
Transcript of LPH 105 W15 11:intro
Energy in SHM
amplitude, frequency, period
Kinetic and potential
Equations of motion
dampened and resonance
Intensity and power
Superposition, interference, and standing waves
types of waves
add not destroy
Simple Harmonic Oscillator
Describe its motion
A spring is an easy example (DEMO)
Repeats, constant in time, distance it travels, speed maximizes
Frequency, period, amplitude, velocity
Frequency = repetitions per second
units = Hertz = 1/s
period = how long it takes to repeat a cycle
units = second
amplitude = distance traveled from equilibrium
simple = frequency is constant
harmonic = motion is sinusoidal (like a sine wave)
oscillation = move back and forth over same path
Note it is faster at places, and it has great displacement at other.
Thus it has KE and PE. And they also cycle back and forth, and between each other.
at some location it has only KE.
at other locations only PE.
But the total energy is constant throughout.
If you are in between the max, you will have both KE and PE
Thus you will have a velocity, at a location away from the equilibrium, and they are related.
With the max velocity and the max position listed as.
x = A
One more analysis
Because we can equate the max KE and PE, we can solve for a relationship of period and frequency
Because the motion is harmonic (like a sine wave) we can describe its position as:
And describe its velocity as:
And acceleration as... ( won't do this one)
Without the fan fare a pendulum is an oscillator and it moves similar to a spring.
Its energies are the same, but period and frequency are as follows.
Notice the mass of the pendulum is irrelevant.
special case of wave on a string
Types of waves
oscillation in direction of wave motion
oscillation 90 degrees to wave motion
Candle or sound
decreases with distance
Solve for constants, and relate.
fixed and free
Add them together
Made from two waves, one going to right, other left
'standing' means long lived, or constant shape
Node = no motion
anti node = most motion
different standing waves can be made, depending on frequency and wavelength.
For some unknown reason to me, we have two terms
that describe these standing waves
n Harmonics overtones
1 1 fundamental
2 2 1
3 3 2
4 4 3
If my fundamental
Frequency is 100 Hz
and I produces another
standing wave that is 400 Hz
which Harmonic is it?
Which of these is not a SHO
A. Mass on spring
D. Car on circular race track
Which of these would increase the time it takes for a mass to return to where it started?
A. Give it a larger initial displacement
B. Increase the spring constant
C. Increase the mass
D. Decrease the mass
E. Increase the frequency
Where is the potential energy of a pendulum the greatest?
A. Where the kinetic energy is negative
B. Where the kinetic energy is positive
C. Where the kinetic energy is zero
D. At the bottom of its swing
E. Depends on where you call y = zero
If I cut the distance I am away from a source in half what happens to the intensity?
B. Stays same
"I saw in the reading that we will be doing more problems with springs, can we go over those again?"
" Why is amplitude not related to those other terms on the prequiz? Question 4. "
"Which of these is not related to the others
Frequency Amplitude Period Wavelength Velocity"
"How are we able to tell the velocity of waves?"
"I still don't understand what harmonic motion is. Could we go over this in class?"