PH101 HW Motion

# PH101 HW Motion - This print-out should have 39 questions....

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This print-out should have 39 questions. Multiple-choice questions may continue on the next column or page – fnd all choices beFore answering. Well, this is a lot oF homework! Most oF them are quite easy anyway, one equation is all you’ll need. I want you to start working an the basic concepts and understand them From the really beginning. I will assign less homework next time. Take advantage oF the Help Center or ask me aFter class or in my o±ce (not by email). 001 (part 1 oF 2) 10.0 points Aph y s i c sbooki sm o v edon c ea r oundth e perimeter oF a table oF dimensions 1 m by 3 m. IF the book ends up at its initial position, what is the magnitude oF its displacement? 1. 6m 2. 1m 3. 4m 4. 2m 5. 7m 6. 5m 7. 8m 8. None oF these 9. 3m 10. 0m correct Explanation: Since its fnal position is the same as its initial position, the displacement is 0. 002 (part 2 oF 2) 10.0 points What is the distance traveled? 1. 2. 3. 4. 5. 6. 7. None oF these 8. 9. 10. correct Explanation: The distance traveled is the perimeter oF the table: d =2 ± +2 w =2(1m)+2(3m) =8m . 003 10.0 points Two ants race across a table 68 cm long. One travels at 5 . 03 cm / sandtheotherat2cm / s. When the frst one crosses the fnish line, how Far behind is the second one? Correct answer: 40 . 9622 cm. Explanation: Let : ± =68cm , v 1 =5 . 03 cm / s , and v 2 =2cm / s . The time it takes the frst (Faster) ant to cross the fnish line is t = ± v 1 , and the distance the slower ant covers in that time is s 2 = v 2 t = v 2 ± v 1 .

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The slower ant is ± - s 2 = ± - v 2 ± v 1 =68cm - (2 cm / s) (68 cm) 5 . 03 cm / s = 40 . 9622 cm from the Fnish line when the faster one crosses it. 004 (part 1 of 2) 10.0 points Abugcomp letesonelapa longtheedgeo fa circular planter of radius 23 . 3cmin10 . 93 s. How fast was it traveling? Correct answer: 13 . 3942 cm / s. Explanation: Let : r =23 . 3cm and t =10 . 93 s . The distance around the circular planter s =2 πr ,sotheve loc ity v = s t = 2 t = 2 π (23 . 3cm) 10 . 93 s = 13 . 3942 cm / s . 005 (part 2 of 2) 10.0 points How fast in m/s? Correct answer: 0 . 133942 m / s. Explanation: v =(13 . 3942 cm / s) 1m 100 cm = 0 . 133942 m / s . 006 (part 1 of 4) 10.0 points Both car A and car B leave school at the same time, traveling in the same direction. Car A travels at a constant speed of 78 km / h, while car B travels at a constant speed of 92 km / h. How far is Car A from school 3 h later? Correct answer: 234 km. Explanation: Let : v a =78km / ha n d t =3h . d = v a t =(78km / h) (3 h) = 234 km . 007 (part 2 of 4) 10.0 points How far is car B from school 3 h later? Correct answer: 276 km. Explanation: Let : v b =92km / h . d = v b t =(92km / h) (3 h) = 276 km . 008 (part 3 of 4) 10.0 points How long does it take car A to reach a gas station a distance 167 km from the school? Correct answer: 2 . 14103 h. Explanation: t = d v a = 167 km 78 km / h = 2 . 14103 h .
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## This note was uploaded on 10/03/2010 for the course PH 101 taught by Professor Jones,s during the Spring '08 term at Alabama.

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PH101 HW Motion - This print-out should have 39 questions....

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