Conservation of momentum and energy

The morning session opened with a silent Smartboard set up.

Then seven diagrams were placed into the board. Without comment. Then the set up was illustrated on the center table without rolling any marbles. When asked, three students thought one marble in would yield one marble out.

Rusty explores the system.

Clayton also exploring the marble system. No vocabulary has been attached at this point.

This summer a table was done on the board and then the students were asked to suss out the mathematical relationship. No one thought to turn to Desmos until that was suggested. One student thought the y-intercept was likely to be zero.

Eventually a student suggested that slope might be one. Only then was the extension made to marbles in equals marbles out, stuff in equals stuff out, mass in equals mass out. Speed in is roughly speed out. Then a 5=5 and 3=3 example led to "therefore the products are equal." 

This led to a more formal definition of momentum.

The banana leaf marble ramp laboratory entails a number of pieces of equipment.

The height rig was operated solo using hairbands as no student opted to assist. Cell phone era.

The end tables are at the back of the room. Meter sticks were the substitute backstop.

The issue of the roll out being disrupted by the joint between the tables was, for the first time, resolved by adjusting the chair location such that the banana leaf extended over the joint. The result was more consistent data that yielded good curves even at a low max height of 55 cm.

One leaf went well past the joint. Larger leaves are not as necessary with this adjustment.

Ruthy "Shannon", Mary-ellen, Eric, Jonald timing. 

Emars records data.

Nicole and Trishia also recording data. Only two rigs were set up. Nicole showing Trishia something on her phone.

Metal marbles were used again this term.

Board set up at class start. The use of Fibonacci based heights is intentional. Produces the most consistent results. Perhaps because the next velocity cannot easily be linearily estimated. Rimes are the median of five runs from each height. This also smooths out errant runs.

This was the derivation of the theoretic relationship.

Board notes at the start were minimalist at best. The right hand column was added after the data was gathered.

The notes on the derivation are on the left, to the right are the morning momentum notes.

The data was very consistent between the groups. Both groups had surprisingly smooth curves.