Here's the question you clicked on:
Denebel
an automobile accelerates from rest at 1+ 3* sqrt (t) mph/sec for 9 seconds. What is the velocity after 9 seconds?
1+3sqrt(9) 1+3(3) 1+9 10mph
^ Wouldn't this find the acceleration at time t, not the velocity?
Good point Xishem... I wondered about that too, but I can't tell from the question X(
Would integrating the function from 0 to 9 give the correct answer?
Hm, when the problem states it like that... does it mean that the velocity is the function 1 + 3*(t) or the acceleration?
the function is of acceleration
so its integral will be velocity
It means acceleration....yeah, Xishem, you're right, this will require integration
Yeah, the book says mph/sec.. how should it be stated if it was giving the velocity?
i would change either the hours to seconds or vice versa
so your answer can be in the form mps or mph
this can be done by dimensional analysis
i get v(t) = t + 2t*sqrt(t) v(9) = 9 +2*9*sqrt(9) = 63 mph
integral of sqrt (t) = [2t^(3/2)]/3 Multiply that by the 3 constant.. = 2t^(3/2) am I doing something wrong? I can't get sqrt (t)
it's the same thing... 2t*t^(1/2)=2t^(3/2)
Oh I see. I would have never though of to do that... makes calculations so much easier, haha.