Questions & Categories
Our questions are marked w/ our names
"Real questions" are unmarked
Coupled Pendulum
Length
- What happens if the length of the strings aren't the same? -K
- How does the length of string affect the period? -K
Mass
- What happens if you make both masses heavier? -K
- What happens if the two masses aren't the same? -K
- what if the masses aren't solids, but liquids? Does this make any difference b/c of momentum?-S
Connection
- Will energy be transferred in the same way if you use a rod v. a string? -K
- Is there any difference if its a rubber band?-S
- How does the tension of the string affect oscillations? -K
- What happens if you move the connecting point farther down? -K
- Does the distance between the connections make a difference? -S
Patterns
- What determines the amount of swings before the motion is passed back and fourth? -K
- What determines if it makes a figure 8 pattern vs. just a line pattern? -S
Materials
- What happens if you use different thickness of string? -K
- what happens if you use different types of string with varying friction? (i.e. fishing line vs. twine) - S
- Does the friction in the connections cause the other bob to start oscillating? -K
QWWNDWATT
- What happens if you add another bob? I QWWNDWATTed this because I think it may be beyond our content goals, what do you think? -K
- Does the direction of the pendulum change due to rotation of the earth? -K
- What happens if you move it sideways? should this be QWWNDWATTed? -K (yes?-S)
- Why does it start twisting? should this be QWWNDWATTed? -K (yes?-S)
Questions from Activity
- Move the strings further from one another. Does the period of the alternating energy change?
- With one long pendulum (first one) and one short one (second string) can we increase the amplitude of the second pendulum? Or is the energy not transferred at all?
- What if we had eight identical pendulums along the length of the string?
- What is the timing (seconds) for each oscillation?
- How does the amplitude change (after each stop)?
- Do both have the same amplitude?
- How long until it stops?
- How does the speed (oscillation) change with length of pendulum and line/distance between the two pendels?
- Does weight change amplitude and speed?
- What happens if you add more pendels?
- Why is this happening? (picture was drawn to explain)
- Does the weight change the pattern if the mass was changed?
- What happens if the distance between becomes very close?
- Setting one pendulum into motionresults in the other pendulum beginning to oscillate. Why?
- Pendulums uneven on strong (center of mass for pendulum system) off center.
- Concepts: Potential energy, tension, kinetic energy, energy transfer, interference
- How does the momentum of one pendulum transfer to the other?
- Why does the 1st pendulum slow while the second one speeds?
- What happens if the two pendulums are suspended from a stiff bar instead of a string?
- What happens when you start them both at the same time on the same side?
- What happens if you start them at the same time from opposite sides?
- How does the distance between the pendulums effect the rate momentum shifts from one to the other?
- What if the pendulums are different weights?
- What’s letting the two pendulums talk to each other?
- What happens when they’re started in phase with each other?
- Not pi/2 out of phase? (just some arbitrary difference)
- What happens with different length pendulums?
- What length leads to interesting behavior?
- If you add more pendulums, what happens?
- How long will they continue to swing?
- Which one will stop first? Is it always the same?
- What happens when you move them further apart? Closer together?
- What happens when you change the lengths?
- What if you start both at once?
- Why does the 2nd pendulum start swinging?
- Would it happen the same if they were hanging from an inflexible rode (instead of the string across the top)?
- Does it work better if the pendulums are closer together or farther apart? Is there some optimal ration?
- Why does the second pendulum start swinging?
- The second pendulum swings longer than the first one—why?
- How is the frequency of the first pendulum related to the second?
- When the second pendulum starts swinging, the first one slows down—why?
Spring Pendulum
Setup 1
- How does PE change with mass?
- What would happen if a "stronger" spring were used?
- What happens if you change the length of the rubber bands?
- At what amount of wieght does it start swinging as well as bouncing?
- What happens when you reduce the weight, add more weight?
- I think the rate she moved the rod with her hand was changing - if you do the same will the still behave differently?
- The heavier weight bounced more slowly, but it also swinged side to side, why?
- Why does it swing and bounce with more weight
- How does the rate of the stick motions affect the rate of bounce/amount of swing?
- How does the mass on the spring effect frequency?
- How are the pendulum & spring coupled?
Setup 2
- Why did it go (^) with added weight?
- Is there a certain amount of weight where the path changes from a regular pendulum swing to the other way?
- By increasing the mass why does the path appear sinusoidal?
- Again what would happen with changing weight?
- Length of rubber bands?
- Why does the pendulum with less weight swing as a smooth acr while the heavier pendulum bounces upward at the midpoint of the swing?
- How does spring strength affect the path of the pendulum?
- Why does the heavier have a bouncy/swingy path while the lighter only a swingy path?
- How are the pendulum & spring coupled?
- How does the mass effect the coupling?
- What is changing in the 2 systems w/ more mass?
- What effects the frequency of a pendulum by itself (ie no springs)?
General Comments
Some of my questions seem to overlap categories with patterns (for instance how does length or mass affect the pattern?) should this be a category of its own?
Dowel Pendulum
Note: backslash signifies/separates individuals questions.
- What speed should you slide the board back and forth for the short one
to move? How bout the other way around?
- Does it work if you slide it back and forth the other way?
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- What is the resonant frequency of the material and how does this
change with length and mass?
- Define oscillation wavelength
- Oscillations vary between lengths why?
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- Reinforcing frequencies increase the amplitude of motion
Which requires more to break?
- What happens if we change the dowel diameter, length?
- What happens if we change the weight?
Easier to break?
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- What effects v of pendulum?
- What driving frequencies will make both resonate?
- Could we couple them w/a spring? What would happen?
- Slide the masses up and down the dowel can we get them at the same
resonance? Why?
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- Why does the short dowel oscillate when the rate of the platform is
faster while the long dowel oscillates only when the platform is
slower?
- Is there an in-between rate that both dowels will oscillate at the same time?
- Is the reason for the difference related to the length only?
- How does the weight of the class balls affect the rate?
- How fast are the oscillations and how do they relate to the platform speed?
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- What happens if you put more weight on short one?
Circle?
- What happens if the distance between became closer?
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- Why do the two pendulums wiggle at different frequencies?
- Can you wiggle at a rate that makes both wiggle?
- What happens if you change the weight of the clay balls?
- Do they need to be the same size/mass for this to work?
- What if you move them using a different type of motion?
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- Did you push with different energy? (left right)
- How long until it stops again?
- Is the weight on the top important?
- What is the lengths of the sticks?
- What is the material used?
- What happens if it's a metal stick?
- How much more amplitude with the metal top?
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- The long pendulum swings when he shakes it slowly and the short
pendulum swings when he shakes it fast? Why?
- What magical pendulum fairies?
- Does it matter if you take the balls of the end?
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