Homework Help: Pls help with one of 2 questions

1. Sep 19, 2007

steve 99

1. The problem statement, all variables and given/known data

I have this questions an answer to it would be great.
.Q.1 At t minutes after an engine starts, the rate of fuel consumption is Rkg per minute. it is given by R=10+ 10/2t+1.

a) Sketch R as a function of t

b) find the rate of consumption after 7 mins

c) find the limiting value of R as t becomes very large

d) calculate the total consumption in the 1st 7 mins

not sure how to do it
Thank You

2. Relevant equations

3. The attempt at a solution

I can do part 2

2. Sep 19, 2007

dynamicsolo

Is that rate supposed to be R = 10+ [10/(2t+1)] ? I think it would be for question (c) to have a sensible answer. The question is asking you what the limit of R is as t goes to infinity.

As for (d), you have a function giving you the *rate* of consumption with time. If you want to know how *much* fuel has been used in the time interval 0 <= t <= 7 minutes, what operation must you perform on the function R(t)?

3. Sep 19, 2007

steve 99

so wat is the function is that R(t)= 10+(10/2t+1)

4. Sep 19, 2007

dynamicsolo

Yes, that is the fuel consumption rate function.

5. Sep 19, 2007

steve 99

so i no the value will not go >10 or equal to 10 but im not sure how to calculate that

6. Sep 19, 2007

steve 99

i no it wll approach but neva touch 10 if you graphed but as i said not sure on the calculations