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Physics 2A Lab Final Spring 2021/Version A (94 pts) MAKE SURE YOU SHOW ALL WORK IN COMPLETE DETAIL

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Physics 2A Lab Final Spring 2021/Version A (94 pts) MAKE SURE YOU SHOW ALL WORK IN COMPLETE DETAIL. NO CREDIT WILL BE GIVEN IF NO WORK IS SHOWN! EXPRESS ALL ANSWERS IN SI UNITS. Lab - Measurements and Error Analysis (16 pts) For the following questions state your measurements and calculations in explicit form (Xbest ± Δx). Only for this lab, express answers in units of cm, g. The following measurements have been made for an aluminum block in the lab: L1= 3.152 cm, L2= 0.932 cm, L3= 4.422 cm M = 35.55 cm 1. What instrument was used to measure the length dimensions? (2 pts) 2. What instrument was used to measure the mass? (2 pts) 3. Calculate the uncertainty in the volume of the block. ( 4 pts) 4. Calculate, in explicit form, the volume of the block. ( 2 pts) 5. Calculate the uncertainty in the density of the block. (4 pts) 6. Calculate, in explicit form, the density of the block. (2 pts) 1 7. Write down the reading for the measurement below using the Vernier calipers. (4 pts) L = _______________________ Lab - The Atwood’s Machine (14 pts) Consider the Atwood Machine diagram shown below. 230 g rod H =1.50 m 200g 2 a) Apply Newton’s 2nd Law to derive and equation for the theoretical acceleration and then use it to calculate the acceleration of the blocks after released from rest. (4 pts) b) It takes the 230-gram block t = 2.18 s to reach the floor when it is released from rest at height of H = 1.50 m above the floor as shown above. Apply the kinematic equations of motion to the block to determine its acceleration. (2 pts) c) Calculate the percent error between the accelerations. Take the value obtained from Newton’s 2nd Law to be the expected value. (2 pts) d) EXPLAIN one systematic error associated with this experiment and how it affected the outcome. (Do not include air resistance) (4 pts) e) EXPLAIN one random error (not due to uncertainties of measuring devices) associated with this experiment and how it affected the outcome. (2 pts) 3 Lab - Centripetal Acceleration (3 pts each) 1. During this lab that net force causing the acceleration of the rotating bob was: a) b) c) d) e) The hanging weight. The tension force. The spring force. The weight of the bob. The centrifugal force. 2. A 0.2 kg stone is attached to a string and swung in a circle of radius 60 cm on a horizontal and frictionless surface. If the stone makes 150 revolutions per minute, the tension force on the string is : a) 0.03 N b) 0.2 N c) 0.9 N d) 1.96 N e) 30 N 3. A car experiences both a centripetal and a tangential acceleration. For which of the following would this be true? a) it is going around a curve at a constant speed b) it is going around a curve and slowing down c) it is going along a straight road at a constant speed d) it is going along a straight road and increasing its speed e) it is going along a straight road and decreasing its speed 4. A particle moving in uniform circular motion is a) in equilibrium because it’s moving at constant speed. b) not in equilibrium because it has a tangential and radial acceleration. c) not in equilibrium because it has an acceleration directed toward center of circular path. d) None of the above. 5. Uniform circular motion is the direct consequence of : a) Newton’s 3rd Law b) a force that is always tangent to the path c) an acceleration tangent to the path d) conservation of energy and momentum e) an acceleration always directed toward the same point Lab – Conservation of Momentum (3 pts each) 1. An elastic collision is a collision in which: a) momentum and potential energy are conserved. b) mass and momentum are conserved. c) mechanical energy is conserved. d) momentum and kinetic energy is conserved. e) all of the above. 4 2. The type of collision that was involved in this experiment was: a) elastic b) inelastic c) perfectly inelastic d) None of the above. 3. The frequency of the spark generator was set at 10Hz. This implies that: a) the period is 10 seconds. b) sparks are generated every 10 seconds. c) the speed of the pucks are 10 m/s. d) sparks are generated every 0.1 seconds. 4. The momentum of a system is conserved when: a) the net transfer of mass across the boundary of the system is zero. b) the resultant external force on the system is zero. c) the resultant external torque is zero. d) mechanical energy is conserved. e) None of the above. 5. After performing this experiment you realized the air-puck table was tilted along the xaxis of your coordinate system. Explain what type of error this is (systematic/random) and what effect will it have on the outcome of the experiment. Lab – Static Equilibrium (30 pts) Short-answer conceptual question (2 pts each) 1. Provide a conceptual and practical explanation of torque. Do not use any mathematical definitions. 2. What is lever arm? 3. How do you define positive torques? 4. How do you calculate the torque due to the weight of an object? 5. What are the units of torque? 5 What follows is the procedure for the Static Equilibrium Lab. Include all your DATA (4 pts), CALCULATIONS (12 pts) and CONCLUSION (4 pts)for this lab after the calculation: PROCEDURE Part 1 1. Weigh the meter stick with the triple-beam balance. 2. Locate the center of mass of the meter stick by balancing with a small clamp. 3. Pivot meter stick about the 25cm mark. Add mass to the 10cm mark until the stick is balanced horizontally (see figure below). pivot point 25cm 10cm M 4. Draw a Free-Body Diagram for the meter stick. 5. Calculate the net torque (sum of the torques) about the 25 cm mark. Do not forget to include the mass of the small clamp used to attach the mass at the 10cm mark. 6. Calculate the tension in the string supporting the meter stick by using ∑ ???? . Part 2 1. Pivot meter stick about the 40cm mark. Add 200g to the 95 cm. Add mass to the 10cm mark until the stick is balanced horizontally. 2. Draw a Free-Body Diagram for the meter stick. 3. Calculate the tension in the string supporting the meter stick by FIRST calculating the net torque (sum of the torques) about the 75 cm mark. Do not forget to include the mass of the small clamps used to attach the masses at the 95cm and 10cm marks. 4. Calculate the tension in the string supporting the meter stick by calculating ΣFy. 5. Compare results for the tension in the string. Take the result from (4) to be the expected value. 6 7 1. 2. 3.