Pulleys
After a brief mention of the formula for momentum, I moved to cover Newton's three laws as formulated from a momentum perspective. Momentum unites the first two laws nicely into variations of the same formula.
I rearranged the tables in A101 and rode my RipStik while a ball balanced loosely in my outstretched hand. I collided with a table on one side of the room, and the ball kept on going. Not as vivid as the outdoor demo I did last spring under the solar panels. The greater speed made a lot of difference.
Then I used the new clothes line rope to hold 8 kg up. I used this to pull me. The 50 cm drop that the table top provided was insufficient to gain much speed. Not much better than 65 cm/s². Still, that provided the numbers I needed to work out what my acceleration must have been. Note that measuring speed post-acceleration, while not ideal, is far easier than timing the acceleration directly. One is rather busy getting accelerated, thoughts of timing are secondary.
The gear used.
The odd table layout I deployed.
The afternoon laboratory focused on pulleys, actual mechanical advantage, ideal mechanical advantage, and efficiency. The RipStik tow rope acceleration in the morning provided the smallest smell of a segue to pulleys.
Jimmy works with a six line block and tackle.
The new spring scales arrived after lab five during the spring term. They worked well, but I had to seriously up my masses to provide sufficient sensitivity for the 1000, 2000, 3000, and 5000 scale.
Tracy handled the masses, Marson pulls, Jane Rose records.
Shane makes notes.
Tina, Risenta, and Rose Ann.
When I say I had to seriously up the masses, I meant into the one, two, three, and four kilogram class.
Mackleen, Risenta
Jimmy, Shane, and Rockson
Board diagrams
I rearranged the tables in A101 and rode my RipStik while a ball balanced loosely in my outstretched hand. I collided with a table on one side of the room, and the ball kept on going. Not as vivid as the outdoor demo I did last spring under the solar panels. The greater speed made a lot of difference.
Then I used the new clothes line rope to hold 8 kg up. I used this to pull me. The 50 cm drop that the table top provided was insufficient to gain much speed. Not much better than 65 cm/s². Still, that provided the numbers I needed to work out what my acceleration must have been. Note that measuring speed post-acceleration, while not ideal, is far easier than timing the acceleration directly. One is rather busy getting accelerated, thoughts of timing are secondary.
The gear used.
The odd table layout I deployed.
The afternoon laboratory focused on pulleys, actual mechanical advantage, ideal mechanical advantage, and efficiency. The RipStik tow rope acceleration in the morning provided the smallest smell of a segue to pulleys.
Jimmy works with a six line block and tackle.
The new spring scales arrived after lab five during the spring term. They worked well, but I had to seriously up my masses to provide sufficient sensitivity for the 1000, 2000, 3000, and 5000 scale.
Tracy handled the masses, Marson pulls, Jane Rose records.
Shane makes notes.
Tina, Risenta, and Rose Ann.
When I say I had to seriously up the masses, I meant into the one, two, three, and four kilogram class.
Mackleen, Risenta
Jimmy, Shane, and Rockson
Board diagrams
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