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Unformatted text preview: rtia the beans are stuck together the blades aren’t strong enough to make them move PHYS115 ‐ Spring 2013 8 Test 1 ‐ 4 March 2013 Question 20 – Two ants, John and Jo hn
Yoko
Yoko, are riding on a record that rotates at 33⅓ rpm. They don’t walk. Yoko is closer to the center than John. 33⅓ rpm Who has the greatest angular speed? a. John b. Yoko c. their angular speeds are equal d. it depends on the record’s rotational mass Question 21 – You have two cars, and the larger one is three times as massive as the smaller one.You and a friend push on them so that their accelerations are equ al. The force on the smaller car is ___________ that on the larg er car. a. 1 3 times b. 2 c. 1 3 times 9 times d. equal to Question 22 – Why is your velocity continuously changing as you ride on a carousel? a. it doesn’t, unless you are on a carousel animal which is constantly moving up and down b. because your direction of motion is continuously cha nging a
c. it doesn’t, because your speed is not changing d. because your speed is continously increasing and dec reasing as your direction changes PHYS115 ‐ Spring 2013 V/a 1d 2a 3b 4b 5a 1 Test 1 ‐ 4 March 2013 angle between two spokes is 360/12 = 30 degrees, so angle between A and B is 2 x 30 = 60 degrees this is 60 / 360 * 2 pi = 1/3 pi or about 1 rad 240 rot/min x 2 pi rad / rot x 1 min/60 sec = 240 x 2 pi /60 rad/sec = 8 pi rad/sec = about 25 rad/s See below: Imagine you suspend the horseshoe; only t second diagram makes sence the time from ½ g t2 = height so time = sqrt(2 x height /g ) = 5.533 sec. In this time speed grows to g x time = 54 m/s 6c it has the greatest vertical speed 7d because of the symmet...
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This document was uploaded on 03/13/2014 for the course PHYSICS 115 at UNL.
 Spring '13
 Cornelis(“Kees”)J.Uiterwaal
 Physics

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