1) List the 3-5 ideas you had (as bullet points) for the slow-motion camera, and what frame rate you in mind for eacm (e.g. 100fps):
Snapping a pencil in half (100fps?)
Snapping a mechanical in half (150 fps?)
Smashing pottery with a hammer (100 fps?)
Cake/water ballon hitting volunteer's face (100 fps?)
Snapping a piece of paper (200 fps?)
Popping paper clip (150 fps?) [which was so cool, by the way]
2) Baseball Idea (Backup project): Finding the baseball-bat "sweet spot" (baseball experiments were our idea first, Jimmy's group!)
Objectives/Questions:
Finding the baseball's acceleration
What is the ball's acceleration?
How much force is exerted on the ball by the bat?
What is the ball or bat's momentum?
Finding the ball's total distance traveled
What is the relationship between the ball's distance and the force expended on the ball by the bat?
How much time does it take to travel the given distance?
How much work does air resistance do throughout the motion?
Examining the ball's deformation at a microscopic level
How much does the ball's deformation vary with the force by the bat?
How does the ball's deformation differ with location at which it is stricken? (i.e if the ball is hit on its center of mass, does the deformation differ in shape/scope than when it is hit on the top?
In this light, how is rotational energy/momentum affected by point of contact?
Materials:
Baseball
Baseball Bat
Tee on which to place baseball
Slow Motion Camera
Meterstick (to measure distance traveled)
Carbon-paper for which to measure final displacements
Spark Learning System
Force detector? (or electronic device used to measure force exerted onto the ball)
Place baseball on a T
Start by hitting with elbows straight, to simplify; later try regular swing
[If we want even more control over the experiment, we could rig up a LEGO ripcord batter to swing a miniature "bat" at a ping-pong ball, or better yet make a full-scale ripcord batter...]
Film slow-motion from the side (so that the T is directly between the camera and the batter) through transparent material with graph-paper markings, like a piece of glass with a graph traced using dry-erase markers, which is right in front of the T (from the camera's POV)
See how much the bat/ball deforms and analyze speed/rotational momentum of the bat and acceleration of the ball
Film slow-motion from above, with graph paper installed below the ball
Film regular-speed from a distance, to measure flight time and sketch trajectory
Variables: Swing speed, ball contact location (which varies almost by itself)
(300-500 fps, regular)
New project 2: Physics of propellers, twisted rubber bands, and ripcords
a) Rubber-band-powered propeller planes Objectives/Questions:
Exploring band's potential energy storage
Is there a linear relationship between number of twists and potential energy?
If so, what is this relationship?
What's the relationship between band material/length and potential energy stored per twist?
Compare to potential energy stored from simply stretching the rubber band
Figuring out the power output of the wound band (as it accelerates the propeller)
Does the band output energy at a linear rate (or does it slow down)?
Does the number of twists affect the rate of energy output?
Does the band's material/length affect the rate of energy output?
Is power output the same when the plane is held still versus allowed to fly?
Explore relationship between wound rubber band and plane's flight
Maximum height reached
Air time
Finding the amount of work that is lost due to friction during the winding and flight
Does this work lost to friction depend on the band material/length?
Does it increase linearly as the number of twists increases?
Procedures:
1. Build plane using given instructions. Mark one tip of the propeller.
2. Attach force sensor to plane using a light string.
3. Wind the propeller/rubber band n number of times with the electric winder. Record time taken to wind and calculate the amount of energy used by the electric winder using its power output specifications.
4. Release the propeller. Using a Spark learning system, graph the force exerted by the plane's propeller versus time. Film the propeller slow-motion from the front and/or side to measure acceleration.
5. Vary n and repeat steps 3 and 4.
6. Change length of the band, and repeat steps 3 and 4.
7. Change band material, repeating steps 3 and 4.
9. Detach force sensor, and tape graph paper to the surface underneath the plane and to a surface on one side of the plane.
10. Wind the rubber band n times and release the plane. Measure initial acceleration using slow-motion film from the top or side, and find maximum height reached and air time by filming the flight with the regular camera.
Film slow-motion from the front (and slightly below, for safety), for propeller acceleration and terminal rotational velocity
Film from the side or top for plane's acceleration (measured using graph paper in the background)
(Can also film the plane's full flight with a regular camera to see how much energy was conserved over the flight)
Variables: number of twists to the rubber band, length/material of rubber band (also take into account wear & tear of the band?)
Calculate expected rotational acceleration/motion of the propellor using elastic torque (?) and compare to measured values
(800 fps, 100 fps, regular) Materials
Plane: http://www.rcplanet.com/ProductDetails.asp?ProductCode=EST3430&click=109537&gdftrk=gdfV23720_a_7c1734_a_7c7524_a_7cEST3430&gclid=CNnVmtOHk7UCFQrznAodI10ALA
5:1 Ratio Rubber Band Winder, for convenience: http://www3.towerhobbies.com/cgi-bin/WTI0001P?I=LXUEZ1&P=8(restocking materials)
(Mechanical Winder link?)
How does the distance the stick is rolled on hands affect initial acceleration and max height of the helicopter? (also energy given)
How does the horizontal speed and acceleration affect initial acceleration and max height of the helicopter? (also energy given)
How does coefficient of friction
Examining work done by air resistance
How does helicopter's flight velocity/time/acceleration compare when dropped from different times?
What is the work done by air resistance onto the plane during motion?
When helicopter is dropped from different location, ie an air-conditioned room vs outside in warmth, how do results vary?
What is the terminal velocity of the helicopter and when is it reached?
Examining other aspects of helicopter's flight
When the helicopter is dropped from different angles, how does the flight time/terminal velocity differ?
What rotational energy/work is done during flight?
Materials:
Ripcord Helicopter
Slow Motion Camera
Spark Learning System
Motion Sensor
Ring Stand
Procedure:
Assemble the Ripcord Helicopter using the box instructions
Attach the Motion Sensor to the Spark
Attach the Motion Sensor to the ring stand so that it is facing downwards
Launch the helicopter upwards towards the motion sensor
Graph the position and velocity graphs on the Spark
Film slow motion from a side view, level with the blades of the helicopter at its original height (100-300 fps)
Film in slow motion using a colored dot on one blade to measure rotations per second and acceleration
Can film with a regular camera against a measured board to find out the maximum height
Finding the amount of work that is lost due to friction during the winding and flight
Things Left To Do:
For experiment 1:
Write up the hypothesis (Matt M.)
One idea: "The net torque on the propeller from the band is approximately (neglecting friction) proportional to the number of twists (equivalently the angle of rotation)"
Clarify the dependent and independent variables (Matt M.)
Upload graphs + data (Matt M.)
Determine the rotational inertia of the propeller (Everyone?)
(Determine the "spring constant" of the rubber band (using a hanging mass)?)
Analyze the results
Check the hypothesis
Calculate the torsion K constant for the spring, if there is a linear relationship between torque and twists as hypothesized
Conclusions: what worked, what didn't, what to draw from this
For the next experiment (energy stored in the band):
Write up the hypothesis (Matt M.)
One idea: "The amount of potential energy stored in the band is (neglecting friction) proportional to the number of twists"
Write up + carry out procedure
Tape string attached to force sensor to the tip of the propeller and record the force needed to keep the propeller from moving after 5, 10, 20, 50, and 100 twists
Take the integral of the best-fit curve (?) to approximate the energy required to twist it 100 times
Create and upload the graphs
Analyze the results
Conclusions
(Remaining question: how much of the energy lost from the airplane system is lost to accelerating the air and how much is lost to friction? Is it possible to run the experiment again in a vacuum chamber or use a propeller that doesn't move much air? That way it might follow simple harmonic motion)
(If more time: vary the length or thickness of the rubber band, checking its "spring constant" with a hanging mass, to see what affects K)
Team Members: Pierre Danly, Matt Mistele, Matt Cerda
Google Doc link:
https://docs.google.com/document/d/1kU-rEVCwEcoTWYBxs4j-0ov-woK06y2hZwfmOhLg6Zo/edit?usp=sharing
Natland Note (4/15/13):
1) List the 3-5 ideas you had (as bullet points) for the slow-motion camera, and what frame rate you in mind for eacm (e.g. 100fps):
2) Baseball Idea (Backup project): Finding the baseball-bat "sweet spot" (baseball experiments were our idea first, Jimmy's group!)
Objectives/Questions:
Materials:
Baseball
Baseball Bat
Tee on which to place baseball
Slow Motion Camera
Meterstick (to measure distance traveled)
Carbon-paper for which to measure final displacements
Spark Learning System
Force detector? (or electronic device used to measure force exerted onto the ball)
Place baseball on a T
Start by hitting with elbows straight, to simplify; later try regular swing
[If we want even more control over the experiment, we could rig up a LEGO ripcord batter to swing a miniature "bat" at a ping-pong ball, or better yet make a full-scale ripcord batter...]
Film slow-motion from the side (so that the T is directly between the camera and the batter) through transparent material with graph-paper markings, like a piece of glass with a graph traced using dry-erase markers, which is right in front of the T (from the camera's POV)
See how much the bat/ball deforms and analyze speed/rotational momentum of the bat and acceleration of the ball
Film slow-motion from above, with graph paper installed below the ball
Film regular-speed from a distance, to measure flight time and sketch trajectory
Variables: Swing speed, ball contact location (which varies almost by itself)
(300-500 fps, regular)
New project 2: Physics of propellers, twisted rubber bands, and ripcords
a) Rubber-band-powered propeller planes
Objectives/Questions:
Does it increase linearly as the number of twists increases?
Procedures:
1. Build plane using given instructions. Mark one tip of the propeller.
2. Attach force sensor to plane using a light string.
3. Wind the propeller/rubber band n number of times with the electric winder. Record time taken to wind and calculate the amount of energy used by the electric winder using its power output specifications.
4. Release the propeller. Using a Spark learning system, graph the force exerted by the plane's propeller versus time. Film the propeller slow-motion from the front and/or side to measure acceleration.
5. Vary n and repeat steps 3 and 4.
6. Change length of the band, and repeat steps 3 and 4.
7. Change band material, repeating steps 3 and 4.
9. Detach force sensor, and tape graph paper to the surface underneath the plane and to a surface on one side of the plane.
10. Wind the rubber band n times and release the plane. Measure initial acceleration using slow-motion film from the top or side, and find maximum height reached and air time by filming the flight with the regular camera.
Film slow-motion from the front (and slightly below, for safety), for propeller acceleration and terminal rotational velocity
Film from the side or top for plane's acceleration (measured using graph paper in the background)
(Can also film the plane's full flight with a regular camera to see how much energy was conserved over the flight)
Variables: number of twists to the rubber band, length/material of rubber band (also take into account wear & tear of the band?)
Calculate expected rotational acceleration/motion of the propellor using elastic torque (?) and compare to measured values
(800 fps, 100 fps, regular)
Materials
Plane: http://www.rcplanet.com/ProductDetails.asp?ProductCode=EST3430&click=109537&gdftrk=gdfV23720_a_7c1734_a_7c7524_a_7cEST3430&gclid=CNnVmtOHk7UCFQrznAodI10ALA
5:1 Ratio Rubber Band Winder, for convenience:
http://www3.towerhobbies.com/cgi-bin/WTI0001P?I=LXUEZ1&P=8 (restocking materials)
(Mechanical Winder link?)
b) Ripcord helicopter (if we have time)
http://www.amazon.com/Prop-Shots-Ripcord-Launch-Helicopter/dp/B003ATGQYC
Similar, but with a ripcord we can pull at a steady rate and a helicopter =)
c) "Helicopter Sticks"
Objectives/Questions:
Materials:
Ripcord Helicopter
Slow Motion Camera
Spark Learning System
Motion Sensor
Ring Stand
Procedure:
Film slow motion from a side view, level with the blades of the helicopter at its original height (100-300 fps)
Film in slow motion using a colored dot on one blade to measure rotations per second and acceleration
Can film with a regular camera against a measured board to find out the maximum height
http://www.amazon.com/Rainbow-Puddle-Jumper-Wooden-Helicopter/dp/B001QJSU24
http://www.amazon.com/Plastic-Dragonfly-Assortment-1-dz/dp/B0035RRPJE/ref=pd_bxgy_t_img_y
Finding the amount of work that is lost due to friction during the winding and flight
Things Left To Do:
For experiment 1:
For the next experiment (energy stored in the band):
(Remaining question: how much of the energy lost from the airplane system is lost to accelerating the air and how much is lost to friction? Is it possible to run the experiment again in a vacuum chamber or use a propeller that doesn't move much air? That way it might follow simple harmonic motion)
(If more time: vary the length or thickness of the rubber band, checking its "spring constant" with a hanging mass, to see what affects K)
RESOURCES