Question

Trying to make equations for movement, grade 12 advanced functions. Where I get d=5t, my book gets d=5t-200. What am I doing wrong? Will explain question more in chat.

Answer 1

whats wrong with the q ?

Answer 2

I attached the answer to the question
I just dont get where they get the subtractions in the equations.

Answer 3

So my equations are d=2t, d=0t, d=3t, d=5t

Answer 4

draw what u get , u will find out ur mistake . ur line passes through center but does the sketched line pass the center ?

Answer 5

If you look at the pictures the asnwers are different then that.What am I missing?

Answer 6

you've juct considered the slip but what about the distance to center ?

Answer 7

I dont understand :S. Why do they get 3t-90 where I just get 3t

We are giving equations as to the speed of mohammed walking. I write d=3t when he walks 3m/s they write 3t-90

Answer 8

when you want to find the function of drawed line you should use both the slip and one point in the line

Answer 9

because he walked 90 step before , he is 90 step far from the center

Answer 10

what u wrote means that he came back to the first plave when ever he changes his speed of walking

Answer 11

geez im drawing a i dont really get how they construct their equations. What are they subtracting? Distance already travelled?

Answer 12

How are they deriving their interval equations?

Answer 13

Sorry guys i feel retarded :S

Answer 14

hi radar

Answer 15

@undeadboss I feel your pain. The graph is showing distance as function of time for Mohammad. The function f(t)=D(istance. Your equations must be such, that when you plug in a specific t it will equal d. Lets take a specific time t. You can select the value of t. and we will check out the function that you have developed for that value of t. It must equal the corresponding d.

Answer 16

Sorry I put wrong name.

Answer 17

@unprovoked is who I meant.

Answer 18

ok lets say t= 55 seconds

Answer 19

thx btw

Answer 20

for t 50 to 55 he was travelling at 3m/s

Answer 21

thats why i get d=3t

Answer 22

they show it as d=3(t-50)+60

Answer 23

lol i know the answer isgonna seem simple once i get it. I guess Im just not understanding what they want from me

Answer 24

Ok at t=55 Mohammad has traveled already 55 seconds. Locate 55 on the horizontal scale and go straight up to the graph on the line now look to the left and we will see what the distance is. It is 60 m, Now notice that at t=55 there is two functions that are given as t=55 is a break point. So for the time from t=50 to t=55 is the time he has gotten a green light and speeds across the intersection.

Answer 25

at 55its 75m

Answer 26

50-55 second,travelling at 3m/s he gets from 60m to75 distance

Answer 27

looks like its d=3(t-(speed for interval))+(distance at which interval started)

Answer 28

d=3(t-(time at start ofinterval))+(distance at which interval started) **

Answer 29

ohhhh, is it adding the amount of time travelled at speed to the previous amount ravelled

Therefore being consistent for the entire duration of thatinterval?

Answer 30

A function of t has to give d for the time at during the time he crossed that intersection. Well at the time he got there he had traveled 60m, and remained there while the light was red (for 20 more seconds) and it takes him 5 more seconds at 3 mps which puts him at a distance of 75 ms. Your function must provide the proper distance for those values of t to include the time from then on when he ran the 100m at 5mps.

Answer 31

i think i got the concept! Thanks radar!

Answer 32

Then I will say good luck with your studies. I do believe you now see how they incorporated the previous distances by the use of constants in the equations.