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Unformatted text preview: cho (hmc594) – Homework 2 – spurlock – (31441) 1 This printout should have 74 questions. Multiplechoice questions may continue on the next column or page – find all choices before answering. 001 10.0 points The Washington Monument in the District of Columbia has a height of 555 ft, 5 in. Express this height in meters. Correct answer: 169 . 291 m. Explanation: 1 ft = 0.305 m and 1 in = 0.0254 m, so h = (555 ft) . 305 m 1 ft + (5 in) . 0254 m 1 in = 169 . 291 m . 002 10.0 points Convert 34 . 4 mi / h to m/s. 1 mi = 1609 m. Correct answer: 15 . 3749 m / s. Explanation: 1 mi = 1609 m 1 h = 3600 s (34 . 4 mi / h) 1609 m 1 mi · 1 h 3600 s = 15 . 3749 m / s . 003 10.0 points The number x = 0 . 0268 has how many signif icant digits? Correct answer: 3. Explanation: All nonzero digits are significant. Any zeros in front of the first nonzero digit are placeholders; zeros between nonzero digits are significant. 004 10.0 points Given braceleftbigg − 10 x − 6 y = 122 4 y − 8 x = 36 Find x . Correct answer: − 8. Explanation: 005 10.0 points Use the quadratic formula to solve − 39 . 375 = 6 t − 3 8 t 2 . What is the larger of the solutions? Correct answer: 21. Explanation: Rearranging the equation we get 3 8 t 2 − 6 t − 39 . 375 = 0 3 t 2 − 48 t − 315 = 0 t = − ( − 48) ± radicalbig ( − 48) 2 − 4(3)( − 315) 2(3) = 48 ± √ 6084 6 . The larger solution is 48 + √ 6084 6 ≈ 21 . 006 (part 1 of 2) 10.0 points In a certain right triangle, the two sides that are perpendicular to each other are 6 . 5 m and 6 . 9 m long. What is the length of the third side? Correct answer: 9 . 47945 m. Explanation: Given : l 1 = 6 . 5 m , and l 2 = 6 . 9 m . Using the Pythagorean Theorem, Hypotenuse = radicalBig l 2 1 + l 2 2 = radicalBig (6 . 5 m) 2 + (6 . 9 m) 2 = 9 . 47945 m . 007 (part 2 of 2) 10.0 points What is the tangent of the angle for which 6 . 5 m is the opposite side? Correct answer: 0 . 942029. cho (hmc594) – Homework 2 – spurlock – (31441) 2 Explanation: When 6 . 5 m is the opposite side, 6 . 9 m is the adjacent, and tan θ = l 1 l 2 = 6 . 5 m 6 . 9 m = . 942029 . 008 10.0 points The figure shows a rhombus whose sides are 20 . 8 cm long. The angle θ is 38 . 6 ◦ . A B C θ D E Find the distance from A to B. Correct answer: 4 . 54438 cm. Explanation: In the rhombus ACDE ( B is on the side AC ), we know that the length of each side is equal, AC = CD = S = 20 . 8 cm cm long and the angle negationslash BCD is θ = 38 . 6 ◦ . In the triangle △ BCD , we have BC = DC cos θ so AB = AC − BC = S − S cos θ = S (1 − cosθ ) 009 (part 1 of 2) 10.0 points While John is traveling along a straight inter state highway, he notices that the mile marker reads 250 km. John travels until he reaches the 147 km marker and then retraces his path to the 161 km marker....
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This note was uploaded on 11/15/2010 for the course PHYSICS 1441 taught by Professor Spurlock during the Spring '10 term at UT Arlington.
 Spring '10
 SPURLOCK
 Physics, Work

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