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Exam 1 assignment in the Week 5 module

Physics

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Exam 1 assignment in the Week 5 module. You must show all your work (math, words, and pictures) in order to get full credit. This includes conceptual questions. 2. Late submissions will be marked down ten points for turning in late. 3. If I find any evidence of the questions online (chegg, slader, ask yahoo, physics discussion boards, anything) then everyone has to retake, and cheaters will get a zero and be referred to the Dean of Students. Please do not risk this. 4. You can work alone or with ONE other person from class. Open notes and text, but no internet or googling or group chats. No two groups can work in the same space. Each partner must turn in their own exam. 5. I will be available for questions, but please only clarifying questions! Not: did we do this right? 6. Good luck! ___________________________________________________________________________________________ 1. In the Tokyo Olympics this summer, American Kathleen Ledecky broke the world record for the 1500m freestyle swim (1.5 kilometers!) with a time of 15 minutes 35 seconds. How fast was Kathy going in miles per minute? (1 mile = 1609m) a. b. c. d. e. 0.003 miles/min 0.06 miles/min 0.1 miles/min 0.08 miles/min 0.002 miles/min 1 Name: Date: 2. The equation for Angular Momentum is L = mvr, where r is a distance, m is mass, and v is velocity. How would you represent Angular Momentum in terms of the fundamental dimensions of [L], [M], [T]? a. [L]2/[T] b. [M][L]2/[T]2 c. [M][L]2/[T] d. [L]2/[T][M] 2 Name: Date: 3. Typically, it takes 5 seconds to hear the sound of thunder after the flash of a lightning bolt one mile away. Use this fact to find the speed of sound in m/s. a. b. c. d. 742m/s 1,202m/s 52m/s 322m/s 3 Name: Date: 4. Biologically speaking, a perfect human sprinter can maintain their maximum acceleration for 2.0 s and reach a maximum speed of 10 m/s in that time. After they reach this maximum speed, their acceleration becomes zero, and they run at constant speed. Assume their acceleration is constant during the first 2.0 s of the race and that they start from rest. How far has the sprinter run when they reach top speed? Hint: Use the max speed to find the sprinter’s acceleration first. a. b. c. d. 10m 20m 30m 40m 4 Name: Date: 5. Adrenaline junkies will occasionally leap from El Capitan, a rock formation 910 m high in Yosemite. Assume a jumper runs horizontally off the top with speed 4.0 m/s and enjoys a free fall until she is 150 m above the valley floor, at which time she opens her parachute. It is important that she is far away from the cliff before opening the chute. How far from the cliff is this jumper when she opens her chute? a. b. c. d. 25m 50m 100m 150m 5 Name: Date: 6. Three vectors are shown in the plane below. The units are in meters. The magnitude and direction of the sum of these three vectors is closest to: a. 16m, 15 degrees b. 27m, 26 degrees c. 48m, 47 degrees d. 56m, 55 degrees 6 Name: Date: 7. A victim with a broken rotator cuff is put into a traction apparatus. Two forces (vectors) A and B of equal magnitude are applied to the arm at 32 degrees as shown. They must combine to produce a force in the x direction of 12.8 N on the patient’s arm. How large should forces A and B be in order to create a combined force of 12.8N in the x direction? a. b. c. d. 3.5N 7.5N 11.5N 20.5N 7 Name: Date: 8. A ball is thrown straight down. Which option best describes the velocity and acceleration of the ball during its path to the ground? Explain your answer for full credit. a. b. c. d. e. v = positive, a = 0. v = negative, a = 9.8 m/s2 up. v = negative, a = 9.8 m/s2 down. v = 9.8 m/s, a = 0. v = 9.8 m/s down, a = 0. 8