Question

help please!
The velocity as a function of time is given as v(t) = 5t−t2 in m/s and t in seconds (s). Consider the time interval from t=0 tot = 11 . Find the time before which the acceleration is positive.

Answer 1

So first take the derivative of the velocity function.

Answer 2

5-2t

Answer 3

now what? :o

Answer 4

solve at each interval

Answer 5

its positive when i plug in 2 and negative when its 3 but neither are the answer ):

Answer 6

of course

Answer 7

sooooo then?

Answer 8

ask raffles

Answer 9

I am thinking...

Answer 10

thinking about what?

Answer 11

the question

Answer 12

lol K thanks for your help nincompoop
-.- get out

Answer 13

you want me to get out? because I can solve this in a snap
I don't know what you're stuck on
velocity is a vector, it is negative when it is going down or to the left (backwards)

Answer 14

Okay help her solve it.

Answer 15

you help her :)
I am interested how'd you approach her ....
I mean the question

Answer 16

I don't really want to help her anymore because someone "knows" how to solve the problem in a snap.

Answer 17

So go!=P

Answer 18

the problem is if I solved it for her, then she wouldn't have solved it... I would have.

Answer 19

maybe I can provide a different problem of the same concept

Answer 20

Walk her to the answer...

Answer 21

it is never my style to give the answer even with solutions

Answer 22

ok well what did you mean by solving at each interval?

Answer 23

at a general (any) interval

Answer 24

let me ask you something, what does the t represent in the function?

Answer 25

time

Answer 26

and what about the time?

Answer 27

velocity always involve what?

Answer 28

position?

Answer 29

YEAH!

Answer 30

distance (position)
so distance as a function of time

Answer 31

acceleration involves what?

Answer 32

velocity and time

Answer 33

change in velocity to be specific

Answer 34

(velocity final - velocity initial)/delta t

Answer 35

riiight

Answer 36

the vector direction of acceleration is the same as the vector direction of velocity, correct or wrong?

Answer 37

correct?

Answer 38

you need to be certain

Answer 39

or I will have @hero help you
he's usually good at pointing out all the proper rudiments

Answer 40

a(t)-5-2t solve for t

Answer 41

Set a(t)=0 and solve for t

Answer 42

OMG THANK YOU RAFFLE!