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Unformatted text preview: gutierrez (ig3472) – HW2 – ditmire – (58216) 1 This printout should have 25 questions. Multiplechoice questions may continue on the next column or page – find all choices before answering. 001 (part 1 of 3) 10.0 points The scale on the horizontal axis is 3 s per divi sion and on the vertical axis 5 m per division. 1 2 3 4 5 6 1 2 3 4 5 6 7 8 9 time ( × 3 s) position( × 5m) What is the initial position? Correct answer: 0. Explanation: At time t = 0, the position is 0. 002 (part 2 of 3) 10.0 points What is the final position? Correct answer: 15 m. Explanation: The final position is read from the graph and is 3 times the vertical scale factor (5 m). p f = 3 (5 m) = 112 . 5 m . 003 (part 3 of 3) 10.0 points What velocity is represented by the graph? Correct answer: 1 m / s. Explanation: The velocity is the slope of the position vs time graph, so v = Δ p Δ t = 3 (5 m) 5 (3 s) = 1 m / s . 004 (part 1 of 3) 10.0 points Consider the plot below describing motion along a straight line with an initial position of x = 10 m. 2 1 1 2 3 4 5 6 1 2 3 4 5 6 7 8 9 b b b b b time (s) velocity(m/s) What is the position at 2 seconds? Correct answer: 11 m. Explanation: The initial position given in the problem is 10 m. b b b b b b b b 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 1 2 time (s) velocity(m/s) The position at 2 seconds is 10 meters plus the area of the triangle (shaded in the above plot) x = 10 m + 1 2 (2 s 0 s) × (1 m / s 0 m / s) = 11 m ; gutierrez (ig3472) – HW2 – ditmire – (58216) 2 however, it can also be calculated: x = x i + v i ( t f t i ) + 1 2 ( t f t i ) 2 = (10 m) + (0 m / s) (2 s 0 s) + 1 2 (0 . 5 m / s 2 ) (2 s 0 s) 2 = 11 m . 005 (part 2 of 3) 10.0 points What is the position at 6 seconds? Correct answer: 25 m. Explanation: The position is 11 m plus the area of the trapezoid from 2 s to 6 s x = 11 m + 1 2 (6 s 2 s) × (6 m / s + 1 m / s) = 25 m ; however, it can also be calculated: x = x i + v i ( t f t i ) + 1 2 ( t f t i ) 2 = (11 m) + (1 m / s) (6 s 2 s) + 1 2 (1 . 25 m / s 2 ) (6 s 2 s) 2 = 25 m . 006 (part 3 of 3) 10.0 points What is the position at 8 seconds? Correct answer: 23 . 6667 m. Explanation: The position is 25 m minus the area of the triangle from 6 s to 8 s x = (25 m) + 1 2 (8 s 6 s) × ( 1 . 33333 m / s 0 m / s) = 23 . 6667 m ; however, it can also be calculated x = x i + v i ( t f t i ) + 1 2 ( t f t i ) 2 = 25 m + (0 m / s) (8 s 6 s) + 1 2 ( . 666667 m / s 2 ) (8 s 6 s) 2 = 23 . 6667 m . 007 (part 1 of 4) 10.0 points Consider the plot below describing the accel eration of a particle along a straight line with an initial position of 28 m and an initial velocity of 9 m / s. 4 3 2 1 1 2 3 4 1 2 3 4 5 6 7 8 9 time (s) acceleration(m/s 2 ) What is the velocity at 3 s?...
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This note was uploaded on 04/13/2010 for the course PHY 303K taught by Professor Turner during the Spring '08 term at University of Texas.
 Spring '08
 Turner
 Physics

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