Universal Gravitation Multiple Choice File

4 Comments

Benjamin Lieberman • 7 months, 1 week agologin to reply

Question #11 doesn't seem to correspond with this unit. There is no mention of apparent weight here. Please advise.

John Ennis • 7 months, 1 week agologin to reply

Benjamin, apparent weight is defined in the Uniform Circular Motion presentation on slide 64. UCM should be covered before gravitation. John https://njctl.org/materials/resources/uniform-circular-motion-presentation/attachments/

Manuel Tejelo • 6 months, 3 weeks agologin to reply

Question #21. Isn't the answer Ta=1/2Tb (c)? The velocity for rocket A will be 2X faster than rocket B since mass A is 4 times mass B. If velocity A is greater then T=2(pi)r/v will be smaller for A than for B.

John Ennis • 6 months, 3 weeks agologin to reply

Manuel, you are absolutely correct - and the Word doc is correct, but evidently the open office text and the pdf file were never updated when this correction was made in 2016. I'll fix it now. Thank you for pointing this out. I solve this problem by using the expression T^3/r^2 = 4 pi^2/GM and ratioed it for case a and case b. Ratios are cool for these types of problems as everything cancels out except for the periods of A and B. John

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