Physics Questions You go for run with your friend. You agree to race each other,
ID: 1429610 • Letter: P
Question
Physics Questions You go for run with your friend. You agree to race each other, running north for 3 miles. For the first half mile, you are going twice as fast as she is. She then picks up her pace, catching up to you right at the end, after a total of about 27 minutes of running 9[C]) Which combination of statements are most accurate? [Enter your answer as a string of the letter options you believe are correct. For instance, if you think options A, D, and E are correct, then enter "ADE" A) The x-component of your velocity vector has the same sign as the x- component of your friend's velocity for the whole race B) Your velocity-time graph has a positive slope C) Your friend's average velocity over the whole run is the same as yours. D) Your friend's instantaneous velocity is constant throughout the run E) Your friend's position-time graph would be less steeply sloped than yours after the first half mile of the run. Correct, computer gets: AC 10IQI) Which list of quantities is most correct? [Enter your answer as a string of the letter options you believe are correct. For instance, if you think options A, D, and E are correct, then enter "ADE"] A) Your time to the half mile mark was 3.50 min. B) Your friend reached the half mile mark after 9.00 min C) You were ahead by about 402.25 meters when you reached the first half- mile D) After your friend quickens her pace, her new speed was 0.12 mi/min E) Your friend's average velocity can be expressed as 0.11f mi/min. Correct, computer gets: CDE 11IC] Suppose that the following day you and your friend run another 3 mile race, this time running half of the race straight north, and then the other half back to where you began. The race plays out identically to the previous day. Pick the statements that are true. [Enter your answer as a string of the letter options you believe are correct. For instance, if you think options A, D, and E are correct, then enter "ADE"] A) On a position-timc chart that simultaneously plots both you and your friend's run, there are less than two points where your graph contacts your friend's graph B) Your friend's position-time graph has a constant slope during the first mile of the race C) Your friend's average velocity over the wholc race's time interval is non- zero D) Your displacement over the entire period of the race is 0 miles E) The slope of your position-time graph switches sign after you reach the 1.5 mile mark. Answer: Not yet correct, tries 7/20 12 Q]) During your second race, after your friend has run the first half of the race, which of the following quantitics is correct? [Assume that positive xx-axis points north and that the origin is where you began the race. Your answer should be a string of all the options you believe to be correct.] A) Your friend completed half the race after running for 14.73 minutes B) You have run a distance of 1.64 miles at this point in the race C) Your position is 1.36 miles at this point in the racc. D) Your position is 1.36î miles at this point in the race E) The displacement between your friend and you is -0.14i at this point in the race Answer: Not yet correct, tries 4/20 lab, your computer analyzes the track left bchind by an At the electromagnet electron in your lab. The computer analysis reveals that the position of the electron is well approximated by the function 7(t) (t3-3t2-4t2 + 12t) for the time interval starting at 0 s and ending at 4 s. Note that the time variable in the formula is assumed to be in s and the distance unit is assumed to be a centimeter 13[W]) At what times was the electron momentarily at rest? [Enter the earlier time in the first answer box and the later time in the second answer box] Correct, computer gots: 1.13E-06 ,3.54E-06 s Hint: You might want to plot the function to get a position-time graph. You could also use some basic calculus. 14TW] What was the x-component of the instantaneous velocity of the electron at time 3 s? Answer: Not yet correct, tries 12/20 Hint: When you are devising a plan for solving this problem, consider some calculus to help you solve this. Also, careful about the units!Explanation / Answer
11 (C) ---------> BCD
12 (Q) ----------> ABD
14 (W) ----------> 11,999967 cm