Clicker Question 1 Which of these is an example of a systematic error? A) differences between four measurements using a stop watch. B) a reading of time if the stop watch reads 2 s before started. C) the recorded value if you mistakenly record 4 s rather than 3 s. Clicker Question 2 Which of these is an example of a random error? A) differences between four measurements using a stop watch. B) a reading of time if the stop watch reads 2 s before started. C) the recorded value if you mistakenly record 4 s rather than 3 s. Clicker Question 3 What is the relative error in the calculated value for F if F= M/R2 and eM = 0.1 and eR = 0.2? A) 0.1 B) 0.2 C) 0.3 D) 0.4 E) 0.5 Clicker Question 3 What is the relative error in the calculated value for F if F= M/R2 and eM = 0.1 and eR = 0.2? A) 0.1 B) 0.2 C) 0.3 D) 0.4 E) 0.5 answer Clicker Question 4 Referring to the table above, what is the probability that a data point differs by 0.59 s or greater? (A) (B) (C) (D) 38 44 56 62 Clicker Question 4 Referring to the table above, what is the probability that a data point differs by 0.59 s or greater? (A) (B) (C) (D) 38 44 56 62 answer Clicker Question 5 Suppose you roll the ball down the ramp 5 times and measure the rolling times to be [3.092 s, 3.101 s, 3.098 s, 3.095 s, 4.056 s]. For this set, the average is 3.288 s and the standard deviation is 0.4291 s. According to Chauvenet‘s criterion, would you be justified in rejecting the time measurement t = 4.056 s? (A) Yes (B) No (C) Give your partner a timeout Clicker Question 5 Suppose you roll the ball down the ramp 5 times and measure the rolling times to be [3.092 s, 3.101 s, 3.098 s, 3.095 s, 4.056 s]. For this set, the average is 3.288 s and the standard deviation is 0.4291 s. According to Chauvenet‘s criterion, would you be justified in rejecting the time measurement t = 4.056 s? (A) Yes (B) No (C) Give your partner a timeout (A) t-score = (4.056 s – 3.288 s) / 0.4291 s = 1.78 s (B) Prob within tscore = 92.5 (C) Prob outside tscore = 7.5 (D) Total prob = 5*7.5 = 37.5 % (E) < 50%, reject Clicker Question 6 What is the correct way to report 653 ± 55.4 m (a) 653.0 ± 55.4 m (b) 653 ± 55 m (c) 650 ± 55 m (d) 650 ± 60 m Clicker Question 6 What is the correct way to report 653 ± 55.4 m (a) 653.0 ± 55.4 m (b) 653 ± 55 m (c) 650 ± 55 m (d) 650 ± 60 m Keep one significant figure Last sig fig of answer should be same order of magnitude as error Clicker Question 7 What is the uncertainty formula for P if P = q/t1/2 (a) (b) (c) (d) (e) dP = [(dq)2 + (dt)2]1/2 dP = [(dq)2 + (2dt)2]1/2 eP = [(eq)2 + (et)2]1/2 eP = [(eq)2 + (2et)2]1/2 eP = [(eq)2 + (0.5et)2]1/2 Clicker Question 7 What is the uncertainty formula for P if P = q/t1/2 (a) (b) (c) (d) (e) dP = [(dq)2 + (dt)2]1/2 dP = [(dq)2 + (2dt)2]1/2 eP = [(eq)2 + (et)2]1/2 eP = [(eq)2 + (2et)2]1/2 eP = [(eq)2 + (0.5et)2]1/2 answer Clicker Question 8 Upon flipping a coin three times, what are the chances of three heads in a row? (a) (b) (c) (d) (e) 1 0.5 0.25 0.125 0.0625 Clicker Question 8.5 What are the chances that two people in this room have a Birthday within one day of someone else? (a) (b) (c) (d) (e) > 80% 60 - 80% 40 - 60% 20 - 40% < 20% Clicker Question 9 Two measurements of the speed of sound give the answers: uA = (332 ± 1) m/s and uB = (339 ± 3) m/s. What is the random chance of getting two results that is this difference ? (A) (B) (C) (D) (E) 2% 3% 4% 8% 40% Clicker Question 10 Two measurements of the speed of sound give the answers: uA = (332 ± 1) m/s and uB = (339 ± 3) m/s. What is the best estimate (weighted mean)? (A) (B) (C) (D) (E) 336.5 ± 2 m/s 336 ± 2 m/s 336.5 ± 0.9 m/s 332.7 ± 0.9 m/s 333 ± 2 m/s b) Best estimate is the weighted mean: Clicker Question # 11 Do you expect a plot of V versus q to be linear? V = d 2kq/lAe0 (A) (B) Yes No