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Unformatted text preview: hiarker (srh959) – oldhomework 06 – Turner – (58220) 1 This printout should have 12 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 16 yards. At this point, he throws a 22 yards forward pass straight downfield perpendicular to the line of scrimmage. What is the magnitude of the football’s resultant displacement? Correct answer: 19 . 4165 yards. Explanation: Let the x direction be parallel to line of scrimmage. Given : ∆ y 1 = 11 yards , ∆ x = ± 16 yards , and ∆ y 2 = 22 yards . ∆ y tot = ∆ y 1 + ∆ y 2 = 11 yards + 22 yards = 11 yards ∆ x tot = ∆ x = ± 16 yards The displacements are perpendicular, so d = radicalBig (∆ x tot ) 2 + (∆ y tot ) 2 = radicalBig ( ± 16 yards) 2 + (11 yards) 2 = 19 . 4165 yards . 002 (part 1 of 5) 10.0 points A commuter airplane starts from an airport located at the origin. First it flies to city A located 110 km away from the airport in a direction 36 ◦ North of East. Next it flies 52 . 4 km at 26 ◦ West of North to city B. Finally it flies 188 km due West to city C. A B C O a c b r α β γ N N E W What is the xcomponent of the vector vector b ? Consider E to be the positive x axis and N to be the positive y axis. 1. b x = b tan β 2. b x = b sin β correct 3. b x = b cos β 4. b x = b sin β 5. b x = b cos β 6. b x = b tan β Explanation: Let : b = 52 . 4 km and β = 26 ◦ . For vectorv = ( v x , v y ) and vectoru = ( u x , u y ) , vectorr = vectoru + vectorv = ( v x + u x , v y + u y ) b β  b x   b y  Also, for β < 90 ◦ (as in this problem), vector b is in the second quadrant; i.e. , its x component is negative and its y component positive: b x = b sin β = (52 . 4 km) sin26 ◦ = 22 . 9706 km ....
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This note was uploaded on 04/23/2010 for the course PHY 303K taught by Professor Nui during the Spring '09 term at University of TexasTyler.
 Spring '09
 NUI
 Physics, Work

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