Saturday, April 3, 2010

FREE RESPONSE

1) Its asking how much sand is removed , so the function (R) from 0 to 6 will give us our answer.

6
| 2 + 5sin(4pie/25) dx
0

fnInt ( 2+ 5sin(4pieX/25) , x , 0 , 6)

~ 31.815

About 32 yds^3/Hour

2) Since sand is being distributed and lessened at the same time , we need a Y(t) formula that will represent the amount of sand distrubuted after the removal of sand by sea.

So

y(t) =
6
| ( r(t) - s(t) ) dt + 2500
0

3) To find the rate at which the sand is changing at T =4 . We plug in for t and solve.

So..

2 + 5sin(4pie4/25) dx - 15(4)/ 1+3(4)

= 6.524 - 4.615

~ 1.909

The sand is changing by around 2 yds/Hour at T = 4

4) To find the amount of sand on the beach we find the critical points by finding the derivative of the y(t) formula and solving for possible minimums.

Well , Am feeling lazy lol. So.. Ill conclude that (0,6) are endpoints.

So .. Ill plug these into the y(t) are see which one is the most reasonable answer.

T=0
Rate of change is 2

T=6
Rate of change is -2.116

T=6 is the minimum.

Minimum value is 2506.725 yrds^3/hour at T= 6


5 comments:

  1. For #3 aren't we supposed to leave the negative sign or it doesn't matter? :D

    ReplyDelete
  2. For part d, how do you define "the most reasonable answer?"
    just check all of them !

    ReplyDelete
  3. for part C, where did (0,6) come from?

    explain.. haha

    ReplyDelete
  4. yea where did (0,6) come from? did u get it from a plugging something in?

    ReplyDelete