Please explain Name Tutorial 9 Homework Tutorial section Torque C. Here\'s how t
ID: 1290452 • Letter: P
Question
Please explain Name Tutorial 9 Homework Tutorial section Torque C. Here's how two different students approached part A. Elizabeth: Since the little brother is half as heavy as her sister, he must sit twice as far from the pivot in order to "compensate" for his lower ight-6 feet instead of 3 feet. we Jill. I used the formula for torque, Fr, where F is force and r is distance from the pivot. Here, the relevant forces acting on the see-saw are gravitational, the weights of the children: Fi "60 pounds and F2- 30 pounds. The big sister sits ri 3 feet from the pivot, and we're solving for r:. The torques must balance: Fur solved for r2 to get 6 feet. 1. The two students got the same answer. Did one (or both) of them get lucky, or are both kinds of reasoning valid? Explain. 2. Are Jill and Elizabeth's reasoning fundamentally the same, fundamentally different, or a mix of those two extremes? Explain. Ill. Screwdriver You need to loosen a really stuck screw. You have a choice between two screwdrivers, both of which you can grip very well. The only difference is that one of them, the bottom one of these drawings, has a thicker handle than the other. From your experience, will one screwdriver be better than the other to use to loosen a very tight screw? What is the physics explanation for your answer?Explanation / Answer
Jill's explaination is mathematically perfect. But Elizabeth's answer is more of a common sense type answer, with not adequate mathematical reasoning.
But both their answers are fundamentally the same. Both use their understanding of torque to answer the question. The way of reasoning is the difference.
The thicker screw driver will be better to loosen a tight screw. In case of thick handle, your fingers are at more distance from the axis than the thin handle. Hence according to torques formula T=Fr, even if you apply same force in both cases the torque will be more if distance from axis is more. More torque means easy loosening of screw.
Hence screw driver with the thick handle.