Q ues tions s hould be c ompleted before the following lec tures : Q 1-7 : W 9 /8 ; Q : F 9 /1 0 ; Q : M 9 /1 3

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1 Student Name: Reading quiz 01, Fall 10 Q ues tions s hould be c ompleted before the following lec tures : Q 1-7 : W 9 /8 ; Q : F 9 /1 0 ; Q : M 9 /1 3 Question 1 To convert 5.0 mm to meters, which multiply factor should you use? Question 2 To convert 5.0 cm 2 to square meters, which multiply factor should you use? Question 3 1 of 15 09/06/ :36 PM

2 What is used as a standard of time? revolutions of Earth around the Sun oscillations of a certain type of light emission rotations of Earth Question 4 Which is used as a standard of mass? standard pound standard kilogram standard gram *Question 5 The micrometer (1 μm) is often called the micron. (a) How many microns make up 8.8 km? (b) How many centimeters equal 8.8 μm? (c) How many microns are in 8.8 yd? (a) Number (b) Number (c) Number *1 Units *2 Units *3 Units *Question 6 A fortnight is a charming English measure of time equal to 2.0 weeks (the word is a contraction of fourteen nights ). That is a nice amount of time in pleasant company but perhaps a painful string of microseconds in unpleasant company. How many microseconds are in 2 fortnights? Number *1 Units Significant digits are disabled; the tolerance is +/-2% 2 of 15 09/06/ :36 PM

3 *Question 7 Earth has a mass of kg. The average mass of the atoms that make up Earth is 40 u. How many atoms are there in Earth? Number *1 Units Significant digits are disabled; the tolerance is +/-2% Question 8 Figure 2-14 gives the velocity of a particle moving on an x axis. What is the initial direction of travel? negative positive 3 of 15 09/06/ :36 PM

4 What is the final direction of travel? positive negative Does the particle stop momentarily? no yes Is the acceleration positive or negative? 4 of 15 09/06/ :36 PM

5 negative positive Is the acceleration constant or varying? varying constant Question 9 Figure 2-15 gives the acceleration a(t) of a Chihuahua as it chases a German shepherd along an axis. In which of the time periods indicated does the Chihuahua move at constant speed? (Multiple answers may be correct) 5 of 15 09/06/ :36 PM

6 A B C D E F G H Question 10 Figure 2-16 shows four paths along which objects move from a starting point, all in the same time interval. The paths pass over a grid of equally spaced straight lines. In the following questions, you will need to rank the paths. If multiple paths rank equally, use the same rank for each, then exclude the intermediate ranking (i.e. if objects A, B, and C must be ranked, and A and B must both be ranked first, the ranking would be A:1, B:1, C:3). If all paths rank equally, rank each as '1'. Rank the paths according to the average velocity of the objects, greatest first. 6 of 15 09/06/ :36 PM

7 Object 1 Object 2 Object 3 Object 4 1. Greatest average velocity 2. Second greatest average velocity 3. Third greatest average velocity 4. Fourth greatest average velocity Rank the paths according to the average speed of the objects, greatest first. Object 1 Object 2 Object 3 Object 4 7 of 15 09/06/ :36 PM

8 1. Greatest average speed 2. Second greatest average speed 3. Third greatest average speed 4. Fourth greatest average speed Question 11 Figure 2-18 gives the velocity of a particle moving along an axis. Point 1 is at the highest point on the curve; point 4 is at the lowest point; and points 2 and 6 are at the same height. What is the direction of travel at time t = 0? positive negative What is the direction of travel at point 4? 8 of 15 09/06/ :36 PM

9 positive negative At which of the six numbered points does the particle reverse its direction of travel? (Multiple answers may be correct) Point 1 Point 2 Point 3 Point 4 Point 5 Point 6 Rank the six points according to the magnitude of the acceleration, greatest first. If multiple points rank equally, use the same rank for each, then exclude the intermediate ranking (i.e. if objects A, B, and C must be ranked, and A and B must both be ranked first, the ranking would be A:1, B:1, C:3). If all points rank equally, rank each as '1'. 9 of 15 09/06/ :36 PM

10 Point 1 Point 2 Point 3 Point 4 Point 5 Point 6 1. Greatest 2. Second greatest 3. Third greatest 4. Fourth greatest 5. Fifth greatest 6. Sixth greatest Question 12 If an object moves along an x axis from x = 5 m to x = 3 m, what is the sign of its displacement? negative positive Question 13 On a plot of position x versus time t for an object s motion, what corresponds to the object s average velocity 10 of 15 09/06/ :36 PM

11 between instant t 1 and instant t 2? inverse of the slope of a line connecting the corresponding points on the plot slope of a line connecting the corresponding points on the plot intercept of the plot on the horizontal axis intercept of the plot on the vertical axis Question 14 An object moves from x = 2 m, past x = 4 m, and finally back to x = 4 m. Does its displacement from start to finish depend on how far past x = 4 m it moves before turning back? yes no Question 15 If a particle is traveling in the positive direction along an x axis while it slows, which of the following describes its acceleration? negative zero positive Question 16 The following equations give the velocity v(t) of a particle in four situations: (a) v = 3; (b) v = 4t 2 + 2t 6; (c) v = 3t 4; (d) v = 5t 2 3. To which of these situations do the equations of Table 2.1 of the Text-book apply? A B C D 11 of 15 09/06/ :36 PM

12 Question 17 In Fig. 2-20, a cream tangerine is thrown directly upward past three evenly spaced windows of equal heights. In the following questions, you will need to rank the windows. If multiple windows rank equally, use the same rank for each, then exclude the intermediate ranking (i.e. if objects A, B, and C must be ranked, and A and B must both be ranked first, the ranking would be A:1, B:1, C:3). If all windows rank equally, rank each as '1'. Rank the windows according to the average speed of the cream tangerine while passing them, greatest first. Window 1 Window 2 Window 3 1. Greatest 2. Second greatest 12 of 15 09/06/ :36 PM

13 3. Third greatest Rank the windows according to the time the cream tangerine takes to pass them, greatest first. Window 1 Window 2 Window 3 1. Greatest 2. Second greatest 3. Third greatest Rank the windows according to the magnitude of the acceleration of the cream tangerine while passing them, greatest first. Window 1 Window 2 Window 3 13 of 15 09/06/ :36 PM

14 1. Greatest 2. Second greatest 3. Third greatest Rank the windows according to the change D v in the speed of the cream tangerine during the passage, greatest first. Window 1 Window 2 Window 3 1. Greatest 2. Second greatest 3. Third greatest Question 18 What is the acceleration of a baseball when it is moving upward after being tossed directly upward? 9.8 m/s 2 upward 9.8 m/s 2 downward 0 14 of 15 09/06/ :36 PM

15 Question 19 What is the acceleration of a baseball when it is moving downward after being tossed directly upward? 9.8 m/s 2 upward 9.8 m/s 2 downward 0 Question 20 What is the acceleration of a baseball when it momentarily stops at its maximum height after being tossed directly upward? 9.8 m/s 2 upward 9.8 m/s 2 downward 0 Question 21 On a plot of a particle s acceleration versus time, which of the following is related to the velocity? area between the plot and the time axis slope of the plot Question 22 To get a particle s change in velocity, which of the following should be integrated with respect to time? position function acceleration function 15 of 15 09/06/ :36 PM