Mastering Physics

9/10/13MasteringPhysics: Print View with Answers Signed in as Rupak Mahapatra , Instructor MAHAPATRA-PHYS218 My Courses Assignments Week 2: Chapter 2 Overview Sign Out ( MPMAHAPATRA18325 ) Course Settings Course Home Help University Phy sic s w ith Modern Phy sic s, 13e Young/Freedman Roster Gradebook Item Library Instructor Resources eText Study Area [ Edit ] Summary View Diagnostics View Print View with Answers Week 2: Chapter 2 Due: 11:00pm on Sunday, September 8, 2013 To understand how points are awarded, read the Grading Policy for this assignment. Kinematic Vocabulary Description: A series of questions designed to sharpen the understanding of terms used to describe motion. One of the difficulties in studying mechanics is that many common words are used with highly specific technical meanings, among them velocity, acceleratio n, position, speed, and displacement. The series of questions in this problem is designed to get you to try to think of these quantities like a physicist. Answer the questions in this problem using words from the following list: A. B. C. D. E. F. G. H. I. J. K. position direction displacement coordinates velocity acceleration distance magnitude vector scalar components Part A Velocity differs from speed in that velocity indicates a particle's __________ of motion. Enter the letter from the list given in the problem introduction that best completes the sentence. ANSWER: B Also accepted: direction Part B Unlike speed, velocity is a __________ quantity. Enter the letter from the list given in the problem introduction that best completes the sentence. ANSWER: I Also accepted: vector Part C A vector has, by definition, both __________ and direction. Enter the letter from the list given in the problem introduction that best completes the sentence. session.masteringphysics.com/myct/assignmentPrintView?assignmentID=2472903 1/10 the final position from the initial position).direction.G. A. session. D.C.C.displacement.B.E.direction The coordinates of a point will depend on the coordinate system that is chosen. For example.C.direction. Type the letters from the list given in the problem introduction that best complete the sentence. coordinates. you can express a two-dimensional vector using a pair of quantities known collectively as __________. Enter the letter from the list given in the problem introduction that best completes the sentence. D. direction. D.velocity. coordinates. Part G Identify the following physical quantities as scalars or vectors.9/10/13 MasteringPhysics: Print View with Answers ANSWER: H Also accepted: magnitude Part D Once you have selected a coordinate system.distance. unless you are interested in the position of an object or event relative to a specific origin. coordinates. D.displacement.distance.B. There is more than one correct answer.displacement.. A.E.G.G. A.velocity. coordinates. coordinates. ANSWER: G Also accepted: distance Part F Consider a physical situation in which a particle moves from point A to point B. position.E. position.g. The __________ of the particle at point A differ(s) as expressed in one coordinate system compared to the other. D. A.B. D.distance.G. position. ANSWER: A. Separate the letters with commas. but the __________ from A to B is/are the same as expressed in both coordinate systems. coordinates. A.masteringphysics. Hint 1. and velocity. position. A. D. coordinates. enter I.velocity. D. but there are several other quantities that are independent of the choice of origin for a coordinate system: in particular. coordinates Part E Speed differs from velocity in the same way that __________ differs from displacement. distance. it is independent of the coordinate system used to describe it (although its vector components depend on the coordinate system).direction. A. displacement. D. This process is described from two coordinate systems that are identical except that they have different origins.distance. you can usually choose the coordinate system origin to be wherever is most convenient or intuitive. Note that the vector indicating a displacement from A to B is usually represented as ⃗ ⃗ − rA ⃗ r BA = rB . Definition of displacement Displacement is the vector that indicates the difference of two positions (e. coordinates. but you should only enter one pair of comma-separated letters.C Also accepted: position. Being a vector.displacement.B. Enter the letter from the list given in the problem introduction that best completes the sentence. ANSWER: K Also accepted: components. position.com/myct/assignmentPrintView?assignmentID=2472903 2/10 . position. In working physics problems.E. position.velocity.J. if the words "vector" and "scalar" fit best in the blanks. Its distance from a tall building is given by 3 x(t) = 31. (.9/10/13 MasteringPhysics: Print View with Answers ANSWER: Exercise 2.73 ^ i m/s Exercise 2. ANSWER: v = 4.0 m/s.8 Description: A bird is flying due east. (a) What is the instantaneous velocity of the bird when t=## s? A bird is flying due east.masteringphysics. you run a distance 200 m east (the + x-direction) at an average speed of 5.0m + (12.4 Description: Starting from a pillar. Part A What is the instantaneous velocity of the bird when t = 6.0 m/s to a post.com/myct/assignmentPrintView?assignmentID=2472903 3/10 . Starting from a pillar.9m/s)t − (0.00s ? Express your answer with the appropriate units. Express your answer using two significant figures.. ANSWER: -0. Express your answer using two significant figures. you run a distance 200 m east (the + x-direction) at an average speed of 5. ANSWER: session. and then run a distance 280 m west at an average speed of 4.0 m/s. Part A Calculate your average speed from pillar to post.0370m/ s )t 3 .( a )t^3.4 m/s Part B Calculate your average velocity from pillar to post. Its distance from a tall building is given by x( t ) = x + ( v )t .. (a) Calculate your average speed from pillar to post.0 m/s to a post. and then run a distance 280 m west at an average speed of 4. Part A Compute the average acceleration during the time interval t = 0 to t . ANSWER: aav = 0 2 m/s session. (a) Compute the . Express your answer using two significant figures. = 40s Express your answer using two significant figures. = 10s Express your answer using two significant figures. The driver accelerates from a stop sign.7 2 m/s Part B Compute the average acceleration during the time interval t = 30s to t = 40s .90 = Exercise 2. The driver accelerates from a stop sign.com/myct/assignmentPrintView?assignmentID=2472903 4/10 . The figure shows the velocity of a solar-powered car as a function of time.7 2 m/s Part C Compute the average acceleration during the time interval . cruises for 20 s at a constant speed of 60 km/h. and then brakes to come to a stop 40 s after leaving the stop sign. cruises for 20 s at a constant speed of 60 km/h. ANSWER: aav = 0 2 m/s Part D Compute the average acceleration during the time interval t = 0 to t . ANSWER: aav = 1.12 Description: The figure shows the velocity of a solar-powered car as a function of time. and then brakes to come to a stop 40 s after leaving the stop sign.. ANSWER: aav = -1..9/10/13 MasteringPhysics: Print View with Answers υx = 8. t = 10s to t = 30s Express your answer using two significant figures.masteringphysics. masteringphysics.18 Description: The position of the front bumper of a test car under microprocessor control is given by x( t ) = 2. The position of the front bumper of a test car under microprocessor control is given by 2 x(t) = 2. ANSWER: a = -1.00 session. ANSWER: ax = 9.0 m Part D Find its acceleration at the second instant when the car has zero velocity.100m/s ) t 6 ..9/10/13 MasteringPhysics: Print View with Answers Part E What is the instantaneous acceleration at ? t = 20s Express your answer using two significant figures.( (0. ANSWER: x = 2.4 2 m/s Part E t = 0 t = 2.com/myct/assignmentPrintView?assignmentID=2472903 s 5/10 .80( m/s)^2 ) )t^2 . (a) Find its position at the first instant when the car has zero velocity. Part A Find its position at the first instant when the car has zero velocity. ANSWER: x = 15.100( m/s)^6 ) )t^6.80m/s ) t 2 6 − (0.17 m Part B Find its acceleration at the first instant when the car has zero velocity.17m + (4.60 2 m/s Part C Find its position at the second instant when the car has zero velocity. ANSWER: a = 0 2 m/s Part F What is the instantaneous acceleration at ? t = 35s Express your answer using two significant figures.7 2 m/s Exercise 2. (b) Find its..17( m) + ( (4. ANSWER: ax = -38. com/myct/assignmentPrintView?assignmentID=2472903 6/10 .masteringphysics.00 s . ANSWER: Part F Draw vx − t graph for the motion of the bumper between t = 0 and t = 2. ANSWER: Part G Draw ax − t graph for the motion of the bumper between t ANSWER: session.00 s . = 0 and t = 2.00 s .9/10/13 MasteringPhysics: Print View with Answers Draw x − t graph for the motion of the bumper between t = 0 and t = 2. (a) What is its speed at the first point? (b) What is the acceleration? An antelope moving with constant acceleration covers the distance 76.0m/s .9/10/13 MasteringPhysics: Print View with Answers Exercise 2.60s .com/myct/assignmentPrintView?assignmentID=2472903 7/10 .34 Description: At the instant the traffic light turns green. traveling with a constant speed of v.19 Description: An antelope moving with constant acceleration covers the distance x between two points in time t.7m/s ..0m between two points in time 6. At the instant the traffic light turns green. (a) How far. Part A How far beyond its starting point does the car overtake the truck? ANSWER: session.. At the same instant a truck. traveling with a constant speed of 16. overtakes and passes the car. Part A What is its speed at the first point? ANSWER: v = = 7. At the same instant a truck.60m/s2 . a car that has been waiting at an intersection starts ahead with a constant acceleration of a. Its speed as it passes the second point is v. overtakes and passes the car. a car that has been waiting at an intersection starts ahead with a constant acceleration of 3.27 2 m/s Exercise 2. Its speed as it passes the second point is 15.masteringphysics.33 m/s Part B What is the acceleration? ANSWER: a = = 1. 22m/s3 is a constant. (a) If the bus's velocity at time t_1 is v_1. Part A What is the speed of the lander just before it touches the surface? The acceleration due to gravity on the moon is 2 1. The engine is cut off when the lander is 5..40 Description: A lunar lander is making its descent to Moon Base I.0 m above the surface and has a downward speed of 0. where alpha is a constant. The lander descends slowly under the retro-thrust of its descent engine.com/myct/assignmentPrintView?assignmentID=2472903 8/10 .0 m above the surface and has a downward speed of 0.80 m/s . The engine is cut off when the lander is 5. where α = 1.masteringphysics.1 m/s Exercise 2. Express your answer using two significant figures. what is its velocity at time t2 = 2.08s ? ANSWER: v = = 6. Part A If the bus's velocity at time t1 = 1. the lander is in free fall.6 m/s .0 m/s Exercise 2.. what is its velocity at time t_2? (b) If the bus's position at time t_1 is x_1. With the engine off.93 m/s session. With the engine . what is its position at time t_2? The acceleration of a bus is given by ax (t) = αt .80 m/s . The lander descends slowly under the retro-thrust of its descent engine.52 Description: The acceleration of a bus is given by a_x(t)= alpha t.9/10/13 MasteringPhysics: Print View with Answers d1 = = 142 m Part B How fast is the car traveling when it overtakes the truck? ANSWER: v1 = = 32.01s is 4. A lunar lander is making its descent to Moon Base I.91m/s . ANSWER: v = 4. . You may ignore air resistance.5m/s2 for a height 69. You may ignore air resistance.33 m Part C How much time does he have to get out of its way before it returns to the height of the top of his head. He releases it at height 2.masteringphysics.08s ? ANSWER: x = 12..84 Description: A flowerpot falls off a windowsill and falls past the window below. which is of height 1.0cm .94 session.85 Description: Sam heaves a shot with weight 16-lb straight upward. Part A What is the speed of the shot when he releases it? ANSWER: v = = 7.310 m Problem 2.88m above the ground? ANSWER: t = = 1.90 m.01s is 5. (a) What is the speed of the shot when he. He releases it at height h_2 above the ground. which is of height 1. giving it a constant upward acceleration from rest of a for a height h_1.90 m.65 s Problem 2. A flowerpot falls off a windowsill and falls past the window below..13m above the ground. what is its position at time t2 = 2.. It takes time 0.92 m/s Part B How high above the ground does it go? ANSWER: h = = 5. It takes time 0.com/myct/assignmentPrintView?assignmentID=2472903 9/10 .420 s to pass this window.420 s to pass this window. a distance 1.99m .9/10/13 MasteringPhysics: Print View with Answers Part B If the bus's position at time t1 = 1. You may ignore air resistance. Part A How far is the top of the window below the windowsill from which the flowerpot fell? ANSWER: l = 0. Sam heaves a shot with weight 16-lb straight upward. giving it a constant upward acceleration from rest of 45. (a) How far is the top of the window below the windowsill from which the.2 = m Problem 2. You may ignore air resistance. v0 . ANSWER: H = Copyright © 2013 Pearson. (a) Find the time at. directly above the Part A Find the time at which the two balls collide. directly above the point where the first ball was thrown upward.. the first ball is at the highest point of its motion. ANSWER: t = Part B Find the value of H in terms of v0 and g so that at the instant when the balls collide. A ball is thrown straight up from the ground with speed v0 . All rights reserved.masteringphysics. Express your answer in terms of the variables v0 and g. Express your answer in terms of the variables H . H . There is no air resistance. There is no air resistance. At the same instant.9/10/13 MasteringPhysics: Print View with Answers Description: A ball is thrown straight up from the ground with speed v_0.. a second ball is dropped from rest from a height point where the first ball was thrown upward.com/myct/assignmentPrintView?assignmentID=2472903 Permissions Support 10/10 . a second ball is dropped from rest from a height H. At the same instant. Legal Notice Privacy Policy session.. and appropriate constants.