PHYS 1441-001 HW3 View Basic/Answers HW3 Begin Date: 2/20/2020 12:01:00 AM -- Due Date: 2/28/2020 11:59:00 PM End Date: 2/28/2020 11:59:00 PM Problem 1 - c2.2.3 : Answer the following question about vectors. Part (a) From the quantities given, please select all that would be categorized as vectors. Scalar quantities have a magnitude and units. Vectors have a magnitude, units, and a direction that is specified in some way. For example, temperature is a scalar quantity. Among those listed, only the following are vectors. 2 20 m/s; south, 4 km; north-west, and 10 ft/s ; straight up, Problem 2 - c2.2.1 : Please answer the following questions regarding vector and scalar quantities. Part (a) Which one of the following is a scalar quantity? Scalars have a magnitude and no direction. Vectors have a magnitude and direction. The only quantity with no direction is time. Part (b) What information do vector quantities convey? Scalars have a magnitude and no direction. Vectors have a magnitude and direction. Part (c) Which one of the following is a vector quantity? Scalars have a magnitude and no direction. Vectors have a magnitude and direction. The only one to have a magnitude and direction is distance. Problem 3 - c2.2.4 : Answer the following question about scalars. Part (a) From the given list, choose all that are examples of scalars. Scalar quantities have a magnitude and units. Vectors have a magnitude, units, and a direction that is specified in some way. For example, speed is a scalar quantity, since no direction is specified. Velocity is a vector. Among the quantities listed, only the following are scalars. Density, Mass, Speed, and Distance Problem 4 - c2.2.6 : Full solution not currently available at this time. The diagram shows four vectors in the x-y plane. Part (a) Select all vectors with an x component of zero. 2 Part (b) Select all vectors with a y component of zero. 3 Part (c) Select all vectors with a negative x component. None of the vectors have a negative x component. Part (d) Select all vectors with a negative y component. 1 Part (e) Select all vectors with a positive x component. 1, 3, 4 Part (f) Select all vectors with a positive y component. 2, 4 Problem 5 - 2.3.7 : The various lines represent paths taken by different people walking in a city. All blocks are square and 102 m on a side. Randomized Variables L = 102 m Part (a) Find the total distance traveled on path C in meters. The total distance is the one block up, five blocks to the right, two blocks down, one block left, one block up, and three blocks left. Therefore d = (L) + (5L) + (2L) + (L) + (L) + (3L) = 13L d = 13 (102 m) d = 1326 m Part (b) Find the magnitude of the displacement from start to finish on path C in meters. The displacement is the one block to the right s = L = 102 m s = 102 m Problem 6 - 2.3.27 : Full solution not currently available at this time. A pedestrian walks d1 = 5.1 km east, then d2 = 10.1 km north. Part (a) What is the magnitude of the pedestrian’s displacement, in units of km? d = sqrt(d1^2+d2^2) d = sqrt(5.1^2+10.1^2) d = 11.315 Tolerance: ± 0.33945 Part (b) What is the direction of the pedestrian’s displacement, expressed as an angle in degrees north of east? θ = atan(d2/d1)/0.0174533 θ = atan(10.1/5.1)/0.0174533 θ = 63.208 Tolerance: ± 1.89624 Problem 7 - c2.4.5 : Full solution not currently available at this time. Each part of the diagram shows two vectors, A and B. Part (a) In which part(s) of the diagram are A • B = 0? Select all that apply. 3 Part (b) In which part(s) of the diagram are A • B > 0? Select all that apply. 1 Part (c) In which part(s) of the diagram are A • B < 0? Select all that apply. 2, 4 Problem 8 - c2.3.3 : When two vectors are added together graphically, one can drag the vectors around (keeping the direction the same) so that the tail of one vector touches the tip of the other. Part (a) If the three vectors in the figure are added together (A + B + C), in approximately what direction will the resultant be? In this problem, we are investigating vector addition. For this case, adding the vectors graphically gives zero displacement, meaning that the final point of the path coincides with the initial point (in the figure below, the vectors form a closed triangle). Therefore, this resultant vector has no length and therefore no direction. Images Figure 1. The three vectors, added graphically, give a resultant vector of zero. Problem 9 - c2.3.6 : Full solution not currently available at this time. Consider the how vectors are summed together. Part (a) Is it possible for two vectors of different magnitudes to add to zero? No Part (b) Is it possible for three vectors of different magnitudes to add to zero? Yes This study source was downloaded by 100000851172647 from CourseHero.com on 08-25-2022 16:42:03 GMT -05:00 https://www.coursehero.com/file/71630812/HW3-solutionpdf/ Problem 10 - c2.3.7 : Full solution not currently available at this time. The diagram shows four examples of the graphical addition of three vectors in the x-y plane. Part (a) Select all cases where the x component of the sum of the vectors is zero. 2, 3 Part (b) Select all cases where the y component of the sum of the vectors is zero. 1, 3 Part (c) Select all cases where the sum of the vectors is zero. 3 Powered by TCPDF (www.tcpdf.org) All content © 2020 Expert TA, LLC
