Independent project: Mechanics topics
Below is a list of possible topics using the tools you have available. Most of them are extensions of experiments you may have already tried. You can use the motion sensor to do a physical experiment. Or you can choose any of the models and do further experiments with variables you may not have investigated. These are also on the reference site ( is links.concord.org ) under “List of possible experiment topics”, along with some photos of possible setups.
As you read through these topics, ask these questions:
· Does this topic interest us and will it be fun to look into it?
· Can we think of a testable question for this topic?
· Do we have the equipment and space to do this physical experiment?
EXPLORE YOUR OWN QUESTION: POSSIBLE MECHANICS TOPICS
A. Continue with the mass-spring system.
B. Explore a pendulum, which has cycles like a mass-spring system.
C. Continue with a parachute system.
D. Explore a ramp-cart physical system to learn about energy and friction.
E. Find some other interesting testable question for which you have the equipment. The measurement tools available to you are a force sensor, a motion sensor, and meter sticks.
A. Continue with the mass-spring system.
· Look for other variables that affect the period, for example, the number of springs.
· Measure the spring constant k of the springs directly and plot that against the period. The spring constant is defined as the change in force divided by the change in length. The units are Newtons/meter (N/m).
· Make a “coupled” system: set up two spring-mass systems side by side (hanging from a common horizontal string) and see if you can get them to pass energy back and forth.
· Try rubber bands as springs.
· Compare the physical experiment with the simulation. Do the results match?
· Try ‘damping’ the system in various ways so it slows down more quickly. What is the pattern of slowing down?
· Try a compound system – spring and mass hanging from a spring and mass.
B. Explore a pendulum, which has cycles like a mass-spring system but the same variables may have a different effect.
· Find the variables that do or do not affect the period. Compare this to the mass-spring system.
· Run the pendulum model and explore the effect of the variables. Compare these results to the mass-spring system.
· Compare the physical with the simulation. Do the results match?
· Make a pendulum and a mass-spring system that have precisely the same period. Try to exactly double the period of both so that they are again exactly the same.
· Make a “coupled” system: set up two spring-mass systems side by side (hanging from a common horizontal string) and see if you can get them to pass energy back and forth.
· Study a “compound pendulum” (two masses in different positions) or a rigid pendulum (rod instead of string).
C. Continue with a parachute system.
· Invent your own parachute, perhaps one where the size or some other feature can be changed.
· Test other objects and determine their terminal velocity -- but nothing that will damage the sensor!
· Find the exact numerical relationship between mass, area, and terminal velocity, either with the model or the physical setup.
D. Explore a ramp-cart system to learn about energy and friction.
· Find the relationships among variables for a cart rolling down a cardboard ramp and across the floor, stopping after a certain distance.
· Explore these relationships with the ramp-cart simulation.
· Take on the distance-prediction challenge: Explore the variables so you can make a cart roll any given distance. Then have the teacher set a ‘challenge’ distance and see if you can make the cart stop there.
· Change variables such as mass of cart, friction, type of surface, slope of ramp – find out what effect they have on stopping distance.
· Use the motion sensor to explore the velocity of the cart. Is the shape the same on the ramp and the floor?
· Use the force sensor to measure the rolling friction of the cart.
· Build a “bonker” – a mass on a pendulum that hits the cart – and explore the motion and energy transfer of this system.
E. Other possible situations:
· Bouncing ball: what is the pattern of decreasing height?
· Go further with a class lab from earlier this year. Ask your teacher for suggestions.
· What else could you explore and measure using force and motion sensors?