Question

a particle is constrained to move along a straight line through O.
it starts initially at D, which is a fixed distance from O in the positive direction&moves at a constant velocity of 4ms^-1 for 15 sec. until; it is 100m from O for a furhter 25 sec, after which it travels in the opposite direction for 20 sec.
the total distance is 180m.

how do i draw a velocity–time graph?
and what is the final displacement of the particle from its initial position?

please help, its for homework

Answer 1

the velocity is constant for the 1st 15 seconds so u have to draw a horizontal line showing no change for the 1st 15 seconds. so if u label what would usually b the y axix as velocity and the x axis as t go up to 4 and draw a straight horizontal line from 0 to 15. after that im confused as to what u wrote

Answer 2

http://monmouth.monmoodle.co.uk//file.php?file=%2F187%2FMEI%20A-LEVEL%20HOMEWORK%20RESOURCES%2FM1%2FM1%20Chapter%20Assessments%2FCA%20Motion%20Chapter%20Assessment.pdf
question2

Answer 3

i cant access a link to a password protected site. u need to print screen and attach the document or sumthing

Answer 4

ok, one sec

Answer 5

i kno it looks a bit weird cause its being copied and pasted from a pdf file

Answer 6

ok cool it looks fine. um next since it remains stationary 4 25 seconds that means it did not move or the velocity is 0 for 25 seconds so from 15 to 25 seconds later(40s) u have to graph a straight horizontal line on the x axis. now at the 15 second mark u cant have 2 y values else it wont b a function so u have to draw an open circle at the begining of ur horizontal line from 15 to 40s

Answer 7

for the next part the easiest thing u can do is find an average velocity that in 20s can take u 180m. this would b 9m/s(180/20=9) so from 40 to to 20s later(60s) draw a straight horizontal line at 9 mark on what would b the y axis

Answer 8

sorry disregard the last part of what i said. i read it wrong

Answer 9

it said in total u traveled 180 miles so u have to subtract however many miles u originally traveled from 180 which would b 120.becaused u traveled 4m/s for 15s so u traveled 60m, then u ddnt travel any meters for 25 seconds. so 180-60=120. so for the final part u can say u traveled at an average rate of 6m/s for 20s to cover the last 120m. so on the y axis draw a horizontal line from 40 to 20s later(60s) at 6 on the y axis

Answer 10

omg sorry since u traveled in the negative direction u have to draw the line at -6 not 6. sry :/

Answer 11

cuz u had negative velocity

Answer 12

thanks you, now i need to try and draw that :)

Answer 13

its not 2 bad. 3 horizontal lines

Answer 14

:)

Answer 15

o n 1 more thing remeber when i said u cant have 2 y values @ 15s u also cant have 2 y values @ 40 seconds so when ur drawing ur last line make sure u start with an open circle

Answer 16

open circle?
u said horizontal lines didnt you?

Answer 17

can you also help me with second part of it?
what is the final displacement of the particle from its initial position?

Answer 18

yes horizontal lines n an open circle represents that u r starting from a point but not including the point. so like when ur drawing ur 2nd horizontal line go to the point draw a small circle around it and then draw a line from it

Answer 19

final displacement should b -20m

Answer 20

it traveled 60m from O

Answer 21

n the velocity in the final stage is -6m/s

Answer 22

ok thanks a lot :)