terry (krt238l This print-out should ha re 22 questions. Multiple-choice questions may continue on the next colunm or page iind all choices before answering. You will have approximately two weeks to complete this homework assignment. (.'ollab oration on homework is encouraged. How- ever. you must submit your own responses. and you may he required to show your in dependent work to your HS Instructor. You are expected to access Quest daily to progress through this homework assignment. 001 (part. 1 01'3} 10.0 points The scale on the horizontal axis is 3 s per divi- sion and on the vertical axis 4 m per division. d 5 time [x 3 s] \\'Fllat is the time represented by the third tic mark on the horizontal axis'.' Answer in units of s. 002 [part 2 of 3} 10.0 points What is the position represented by the fourth tic mark on the vertical axis. Answer in units of m. 003 (part 3 of3] 10.0 points What is the position when t 9 s'.' Answer in units of m. 004 10.0 points The graph shows the velocity u as a function of time t for an object moving in a straight line. Homework 2. 1d motion 23-2-1 tejcda {Han'isoanHYl '3) l U | :4.) tit :3 ti' \"'hich graph shows the corresponding dis placement :1: as a function of time t for the same time interval? -: l'""" .M DI terry (krt2368) - Homework 2, 1d motion 23-24 - tejeda - (Harrison.JPHY1_3) 2 Suddenly a child runs into the street. If it takes Ann 0.761 s to react and apply the brakes, how far will she have moved before to tR ts tp she begins to slow down? Answer in units of m. 005 (part 1 of 2) 10.0 points A runner is jogging in a straight line at a 009 10.0 points steady v.= 6.4 km/hr. When the runner is The graph shows position as a function of L= 4.2 km from the finish line, a bird begins time for two trains running on parallel tracks. flying straight from the runner to the finish At time t = 0 the position of both trains is 0 line at v= 12.8 km/hr (2 times as fast as (at the origin). the runner). When the bird reaches the finish line, it turns around and flies directly back to position the runner, finish line What cumulative distance does the bird time travel? Even though the bird is a dodo, as- tB sume that it occupies only one point in space (a "zero" length bird), travels in a straight line, and that it can turn without loss of Which is true? speed. Answer in units of km. 1. Both trains speed up all the time. 006 (part 2 of 2) 10.0 points 2. In the time interval from t = 0 to t = tp. After this first encounter, the bird then turns train B covers more distance than train A. around and flies from the runner back to the finish line, turns around again and flies back 3. Somewhere before time to, both trains to the runner. The bird repeats the back and have the same acceleration. forth trips until the runner reaches the finish line. 4. Both trains have the same velocity at How far does the bird travel from the be- some time before to. ginning (including the distance traveled to the first encounter)? 5. At time to, both trains have the same Answer in units of km. velocity. 007 10.0 points 010 10.0 points A reconnaissance plane flies 482 km away from The following acceleration vs time plots show its base at 838 m/s, then flies back to its base data gathered from an automobile fitted with at 1257 m/s. an accelerometer. In each case the driver ac- What is its average speed? celerated to cruising speed and then slammed Answer in units of m/s. on the brakes. In one case the car is equipped with an antilock braking system (ABS), while 008 10.0 points in the other the car is not. ABS tends to Ann is driving down a street at 60 km/h. prevent skidding and did just that in this ex- periment, allowing a more rapid deceleration.terry (krt2368) - Homework 2, 1d motion 23-24 - tejeda - (Harrison.JPHY1_3) 3 Henry hits a hockey puck in the positive r-direction at time, t = to. The puck is then stopped by a net starting at time, t = t1. Which of the following curves could de- scribe the acceleration of the hockey puck if we ignore any effects of friction? Time (seconds) 1 to 2. " to 6 Time (seconds) Which data set, the upper or lower, more likely came from the car equipped with ABS, and why? 3. to 1. Upper case, because of data between 2.5 and 6.5 seconds to 2. Upper case, because of data between 6.5 and 9 seconds 4 3. Upper case, because of data between 9 and 10 seconds 4. Lower case, because of data between 6.5 5. t1 and 9 seconds 5. Lower case, because of data between 2.5 and 6.5 seconds 6. Lower case, because of data in the first 6. 2.5 seconds to 7. Upper case, because of data in the first 2.5 seconds 8. Lower case, because of data between 9 7 and 10 seconds $1 to 011 10.0 pointsterr}r (krtZSIBSH Homework 2. 1d motion 23-21 tejeda (HarrisorLlPI-[Yl '3) :l 8. None of these graphs are correct. 012 10.0 points A tennis ball with a speed of 1.9.9 mfs is moving perpendicular to a wall. After stri the wall. the ball rebounds in the opposite direction with a speed of 18.41??? mfs. 1f the ball is in contact with the wall for 0.01.37 s. what is the average acceleration of the ball while it '. in contact with the wall'? Take "toward the wall" to be the positive direction. Answer in units of mfsg. 013 10.0 points A ("it-kilogram sports car accelerates uni formly from rest. reaching a speed of 30 me ters per second in 6 seconds. \"That distance has the car traveled during the 6 seconds? 1. 180 in 2. 60 m 3. 15 n1 4. 90 n1 5. 30 n1 014 (part. 1 of 2) 10.0 points A car initially at rest on a straight road accelerates according to the acceleration vs time plot. 'What is the best description of the motion of the car'? Take forward to he the positive direction. 1. The car starts at rest. accelerates to a low speed. comes to a stop. accelerates backwards and cruises in reverse. 2. The car goes forward and then goes back ward. ending behind where it started. 3. The car goes backward and then goes fonvard. 4. The car goes forward and then goes back ward. ending where it started. 5. The car starts at rest. accelerates to a high speed. cruises for a short while. decelerates to a lower speed. then cruises. 6. The car starts at rest. goes up to a high speed. stops moving. travels backward. and stops. 015 (part. 2 of 2) 1.0.0 points Which of the following graphs describes the velocity vstime of the car'.' terry (krt2368) - Homework 2, 1d motion 23-24 - tejeda - (Harrison.JPHY1_3) 5 ground at t2- Which of the following curves could de- 1. scribes the acceleration of the rock? 5. None of these graphs is correct. 1. a t4 2. 7 3. $1 4. None of these graphs is correct. to ta 5. 12 t3 to 016 10.0 points 6. You are trying to find out how high you have to pitch a water balloon in order for it to burst when it hits the ground. You discover that the balloon bursts when you have pitched it to a height of 18 m. With what velocity did the balloon hit 7. -F the ground? The acceleration of gravity is 9.8 m/s . The positive direction is up, so the velocity when it hits is negative. Answer in units of m/s. 8. 017 10.0 points t2 Henry has tossed a rock upward. It has already been released and is moving upward at time t = 0, turns around at 1, and hits theterry (krt2368) - Homework 2, 1d motion 23-24 - tejeda - (Harrison.JPHY1_3) 9. 018 10.0 points During a baseball game, a batter hits a high pop-up. If the ball remains in the air for 5.47 s, how high above the point where it hits the bat does it rise? Assume when it hits the ground it hits at exactly the level of the bat. The acceleration of gravity is 9.8 m/s. Answer in units of m. 019 10.0 points An engineer in a locomotive sees a car stuck on the track at a railroad crossing in front of the train. When the engineer first sees the car, the locomotive is 400 m from the crossing and its speed is 23 m/s. If the engineer's reaction time is 0.61 s, what should be the magnitude of the mini- mum deceleration to avoid an accident? Answer in units of m/s'. 020 (part 1 of 3) 10.0 points A tennis ball is dropped from 1.21 m above the ground. It rebounds to a height of 1.05 m. With what velocity does it hit the ground? The acceleration of gravity is 9.8 m/s'. (Let down be negative.) Answer in units of m/s. 021 (part 2 of 3) 10.0 points With what velocity does it leave the ground? Answer in units of m/s. 022 (part 3 of 3) 10.0 points If the tennis ball were in contact with the ground for 0.0127 s, find the acceleration given to the tennis ball by the ground. Answer in units of m/s"