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Unformatted text preview: This printout should have 11 questions. Multiplechoice questions may continue on the next column or page – find all choices before answering. 001 10.0 points A quarterback takes the ball from the line of scrimmage, runs backward for 11 yards, then runs sideways parallel to the line of scrim mage for 14 yards. At this point, he throws a 49 yards forward pass straight downfield perpendicular to the line of scrimmage. What is the magnitude of the football’s resultant displacement? Correct answer: 40 . 4969 yards. Explanation: Let the x direction be parallel to line of scrimmage. Given : ∆ y 1 = 11 yards , ∆ x = ± 14 yards , and ∆ y 2 = 49 yards . ∆ y tot = ∆ y 1 + ∆ y 2 = 11 yards + 49 yards = 38 yards ∆ x tot = ∆ x = ± 14 yards The displacements are perpendicular, so d = radicalBig (∆ x tot ) 2 + (∆ y tot ) 2 = radicalBig ( ± 14 yards) 2 + (38 yards) 2 = 40 . 4969 yards . 002 (part 1 of 5) 10.0 points A commuter airplane starts from an airport located at the origin (see figure). First it flies to city “A” located a = 100 km away from the airport in a direction α = 34 ◦ North of East. Next it flies b = 61 . 2 km β = 33 ◦ West of North to city “B”. Finally it flies c = 170 km due West to city “C”. A B C O a c b r α β γ N N E W Consider “E” to be the positive x axis and “N” to be the positive y axis. Which of the following is equal to the x component b x of the vector vector b ? 1. b x = b cos β 2. b x = b sin β correct 3. b x = b cos β 4. b x = b tan β 5. b x = b tan β 6. b x = b sin β Explanation: Let : b = 61 . 2 km β = 33 ◦ Basic Concepts: The rule for adding two vectors vectorv = ( v x , v y ) and vectoru = ( u x , u y ) is vectorr = vectoru + vectorv = ( v x + u x , v y + u y ) thus vector components add....
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This note was uploaded on 03/26/2010 for the course PHY 303K taught by Professor Turner during the Fall '08 term at University of Texas at Austin.
 Fall '08
 Turner
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