Question

velocity

Answer 1

instantaneous velocity

Answer 2

will u specify what does x and y coordinate represent?

Answer 3

well, i think the x axis is for time and y's for distance

Answer 4

velocity=displacement/time
here we are required to find velocity at a particular moment,so to find instantaneous velocity at any time u need to find the slope of the graph at that point

Answer 5

yes, thats the formula for velocity.. and how do i get the slope? =)

Answer 6

ah! m= y2-y1/x2-x1

Answer 7

my.. points are? how to determine

Answer 8

yes,u r ryt about the slope.the formula u wrote for slope is correct.
for the first one,at t=2.7 s
check the points including the given point between which the graph's curve doesnt change.then find the slope taking any two points between them.in this case,the graph is same from 1.5 to 3.5. now choose any two coordinates between this interval and u will get IV for t=2.7s

Answer 9

points within 2.7s?

Answer 10

points within 1.5 to 3.5 as u can see the graph doesnt change its shape between these points

Answer 11

and the value u will find will be instantaneous velocity at all the times lying in this interval

Answer 12

it could be 2.5, 3

Answer 13

yes

Answer 14

so.. what do we do next? hehe

Answer 15

am i right? ooooorr

Answer 16

no.m=y2-y2/x2-x1
so u need to use the corresponding y coordinate also
like, we select points (1.5,-60) and (3,-60)
now m=-60-(-60)/3-1.5=0/1.5=0
so instantaneous velocity is zero at 2.7s

Answer 17

thank you.. now. i'll try 5.4s

Answer 18

i guess points are (0, 4.5)

Answer 19

and (5.4, 100)??

Answer 20

ok.see that at t=5.4s, the graph is moving upwards in the same way.now the graph is moving up in this way for a interval.selecting two points in this interval,we choose (5,80) and (6,140).now to find m=140-80/6-5=60
so instantaneous velocity at 5.4 s is 60 m/s

Answer 21

the points u considered were also write but the first point is not(0,4.5),it is (4.5,0)
u exchanged x and y coordinates

Answer 22

yay thank you.. now, ill try 8.8s.. hehe

Answer 23

ok

Answer 24

i think the IV @8.8 is -20? since its going downwards??

Answer 25

yes.u r right.

Answer 26

ok, yey wait..

Answer 27

waiting...........................................................

Answer 28

it could be also -40? or not?

Answer 29

no.it cant be.a body cannot have two different velocities at the same moment.
anyways how did u come up with -40??????

Answer 30

ah nothing. hehe.. so @ 11.5.. the IV is 40?

Answer 31

is the graph vertical at 11.5??????

Answer 32

nope..

Answer 33

first of all,its not 40 and it shud be negative as the graph is going down indicating that the velocity is in opposite direction

Answer 34

ah, human error.. tsk. my points are (11,0) (12,-60)

Answer 35

at t=11,the y coordinate is 100.the second point is correct

Answer 36

-160

Answer 37

sorry but u shud consider the second point here as at t=12 the graph is horizontal,u need to find any other point on the graph while going down

Answer 38

the graph is not quite proper,so it quite difficult to locate points on it

Answer 39

shud not*

Answer 40

in the actual graph, 12 is in horizontal axis with -40

Answer 41

11's is in line with 60

Answer 42

fine.i mtelling u two x coordinates,find their corresponding y coordinate and find the slope

11 and 11.5

Answer 43

isnt -100?

Answer 44

i got (11,60) (11.5, -40)