Someone please explain 'Distance, speed and time' in differentiation...

snooleen

It just won't go into my head! Am doing OL, dropped from HL, but still cant grasp this topic! Ugh. It's the whole ds/dt, dt/ds blah blah thing that confuses me about it. No one ever explained which one was which! Didn't help that I haven't had a teacher since the mocks..

MaggieNF

if your one about the differentiation question, when writing it down you don't actually have to say whether it is ds/dt you can just say dy/dx you won't lose marks....

sheep-go-baa

Okay you are given s, distance.

You differentiate it once and get ds/dt, this is speed, how distance is changing time as time goes on.
I'm not sure how much you do in ordinary level, is explanation that ok?

snooleen

so you dont have to write ds/dt as in speed in relation to time? It's that part I don't understand, I don't get what ds/dt is, is it speed in relation to time? Or distance? Or what?

gant0

The d on top is the constant to the left of the equals sign and the d on the bottom is constant to the right of equals sign.........y=3x............Dy/Dx
x=3y...........Dx/Dy

Sigi

s is distance,t is time and d is short for delta,which is change.
So change in distance over change in time will give you speed.
eg.10km over the course of 1 hour..s=10,t=1 so speed = 10kmph.

kfpt

same boat as u dropped down frm honours last week!

ds/dt is differenciating distance with time = speed

differenciate the value for speed and u get accelleration

hope this helps!

sheep-go-baa

snooleen wrote: »

so you dont have to write ds/dt as in speed in relation to time? It's that part I don't understand, I don't get what ds/dt is, is it speed in relation to time? Or distance? Or what?

ds/dt IS speed, your actual speed at any given time. The definition of speed is how much distance per unit of time. So the change in distance in relation to time (ds/dt) is speed.

Any better?