EF 152 Exam 1 Spring 2018 Version 1 Page 1 Copy 640

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1 EF 152 Exam 1 Spring 2018 Version 1 Page 1 Copy 640 Name: Seat Assignment: Specify your EXAM ID on the right. Use 000 if you don t know your exam ID. Circle your TEAM SECTION A102 A216 A217 A :10 Heather Jonathon Clint Matthew B102 B216 B217 B218 9:40 Heather Jonathon Clint Matthew C102 C216 C217 C218 11:10 Landon Jonathon Clint Matthew D102 D216 D217 D218 12: Justin CJ Landon Cole E102 E216 E217 E :10 Heather CJ Landon Cole : F216 CJ F217 Justin F218 Cole Instructions Do not open the exam until instructed to do so. Do not leave if there is less than 5 minutes to go in the exam. When time is called, immediately stop writing, remain seated, and pass your exam to the center aisle. Working after time is called results in an automatic deduction. Turn your equation sheets in with your exam. Guidelines Assume 3 significant figures for all given numbers unless otherwise stated Show all of your work no work, no credit Write your final answer in the box provided Include units for all answers

2 EF 152 Exam 1 Spring 2018 Version 1 Page 2 Copy (2 pt) What best represents the support reaction for the fixed end of a cantilever beam? Ry Ry Ry Rx M Rx Rx y x 2. (2 pt) A box is at rest on a ramp. Jeremy Pruitt pushes the box with a force P parallel to the top of the box. Using the given coordinate system, which of the following is the correct equilibrium equation for forces on the box in the x direction if you want to determine the minimum force P required to slide the box up the incline? P sin 30 = 0 P 200 sin 30 - s N = 0 P 200 sin 30 - N = 0 P 200 cos 30 - s N = 0 3. (2 pt) A force P is just sufficient to cause a box of uniform density weighing 100 N to begin to tip forward about point C. What is the best point to sum moments about to solve for the force P? Point A Point B Point C Point D P D A C B 4. (2 pt) Which is a valid SI unit for strain? inches meters Pascal unitless 5. (2 pt) What is the definition of stress? Force Length Area Elastic Modulus Force Area change in length original length change in legnth final length

3 EF 152 Exam 1 Spring 2018 Version 1 Page 3 Copy (2 pt) A nylon rope supports a load of 185 lbs. If the minimum required factor of safety is 5, which is the smallest diameter rope that can be used? 3/16 in diameter Strength 200 lbs 1/4 in diameter Strength 300 lbs 5/16 in diameter Strength 500 lbs 3/8 in diameter Strength 900 lbs 1/2 in diameter Strength 1250 lbs 7. (2 pt) The average distance from the earth to the sun is 1 AU. A hypothetical planet orbits the sun a distance of 3 AU. What is its orbital period? 2.08 years 3.0 years 5.2 years 9.0 years 8. (2 pt) A planet has an elliptical orbit. The speed of the planet is 20 km/s when it is furthest from the sun. Which best describes the planet's speed when it is nearest the sun? slower The same faster 9. (2 pt) A 2.7 gram ping pong ball (SG<1) is suspended underwater by a string. Which is a correct FBD? T T W W W W F b F b T F b F b T 10. (2 pt) Assuming an average air density of 0.78 kg/m 3, what is the standard atmospheric pressure on the top of Mount Everest, 8850 m above sea level? (Standard Pressure at Sea Level = kpa). Pabs=33.6 kpa Pabs=94 kpa Pabs=101.3 kpa Pabs=108 kpa Pabs=169 kpa

4 EF 152 Exam 1 Spring 2018 Version 1 Page 4 Copy (2 pt) Dr Hargrove drains her swimming pool through an outlet pipe in the bottom. If it takes 140 minutes to completely drain the pool with 8 ft of water, how long does it take to completely drain the pool with only 4 ft of water? time < 70 min time = 70 min 70 min < time < 140 min time = 140 min 12. (2 pt) Jon blows across the top of a piece of paper. Which is true? P top P bottom ptop = pbottom ptop > pbottom ptop < pbottom (v1 ptop ) 2 = (v2 pbottom) (2 pt) A baseball pitcher throws a curve ball and spins the ball counterclockwise looking from above the ball. According to Bernoulli s Principle and the Venturi Effect, the ball will tend toward what direction due to the spin? left right up No effect 14. (2 pt) The viscosity of water is Pa s and the viscosity of canola oil is 0.05 Pa s. According to Poiseuille s Equation, with all else equal, how much faster is the volume flow rate of water than canola oil? 2500 times 50 times 5 times No effect

5 EF 152 Exam 1 Spring 2018 Version 1 Page 5 Copy (6 pts) What is the maximum load this 7000 lb crane can lift without tipping? Assume the center of mass is centered on the wheels. Rope 16. (6 pts) A satellite is launched from a plane at an altitude of 2000 km. Assuming a circular orbit, what is the ratio of its escape speed to its orbital speed? (G=6.6742x10 11 N m 2 /kg 2, Earth mass = 5.97x10 24, Earth radius = 6380 km) 17. (6 pts) A diver s pressure gage changes by 26 psi as he swims up from a depth of 80 ft below the surface of the water. Determine his new depth.

6 EF 152 Exam 1 Spring 2018 Version 1 Page 6 Copy (6 pts) Water enters a tank of diameter 2.2 m at a mass flow rate of m 3 /sec m 3 /sec of water is draining out of a 0.2 m diameter leak in the bottom of the tank. How fast is the tank filling up in m/sec? 2.2m 0.2m 19. (12 pts) A 12 ft long, 50 pound beam has an inclined load. What is the magnitude of the reaction at B? A free body diagram is required for full credit. y x

7 EF 152 Exam 1 Spring 2018 Version 1 Page 7 Copy (12 pts) A solid cylindrical nanotube is bonded to the inside of a square shaped matrix. A tensile axial load is applied to the system. What is the force in the nanotube if the stress in the matrix is 110 kpa? matrix nanotube Length (nm) Area (m 2 ) 1.5x x10-16 E (10 9 Pa) (12 pts) Underground water is to be pumped to a pool 30 m above the pump at a constant flow rate. The flow speed of water just after it leaves the pump is 0.5 m/s. Water is entering the pool at a speed of 2.88 m/s, and is exposed to the atmosphere. Determine the required gage pressure in the pump. (Assume no losses) 30 m

8 EF 152 Exam 1 Spring 2018 Version 1 Page 8 Copy (12 pts) A straight stretch of horizontal pipe having a diameter of 5 cm is used in the to measure the viscosity of crude oil ( = 920 kg/m 3 ). During a test run a pressure difference of 17.5 kpa is obtained from two pressure gages, which are located 6 m apart on the pipe. Oil is allowed to discharge into a weighing tank, and a total of 510 kg of oil is collected for a duration of 3 min. Determine the viscosity. of the oil. 6 m