Question

please help me with this

The rectilinear motion of a particle if given by 〖s=v〗^2-9 where s is in feet and v in feet per second. When t=0, s=0 and v= 3 fps. Find the s-t, v-t and a-t relations.

Answer 1

that is s= v^2 - 9

Answer 2

Josh: As stated (s=v^2-9), this is a highly unusual problem. Have you any way of taking and sharing a photo of the original problem, so that I could see where you're starting from? Is this problem from a Calculus class?

Answer 3

its physics actually

Answer 4

That's OK. Same question: could you share an image of the original problem with me, so that I could see where you're coming from?

Answer 5

its a .doc file send by my teacher

Answer 6

Thanks. Great how we can share docs so easily. Josh: Have you any class notes, worked examples, examples in your textbook or the like, pertaining to "variable acceleration?" While familiar with physics and the calculus involved here. I'm having trouble visualizing what we need to do. Can you share anything else with me that would give us cues?

Answer 7

ok wait for a sec i;ll take pics on my notes

Answer 8

here it is

Answer 9

sorry its quite blurry... my camera sucks

Answer 10

Josh: I've had a connection problem. But now I can view your photo and will look it over.

Answer 11

I need to know whether or not you've had experience with solving first order linear differential equations.

Answer 12

ok mathmale

Answer 13

yes i've had experience solving first order linear D.E

Answer 14

Cool. That may be the key to solving this problem.

Answer 15

ok i will try it

Answer 16

is it possible??? to use D.E instead of diff. cal or integral?

Answer 17

Josh: Not getting very far, so I'll share with you where I am now and let you decide how to proceed next.

If s=v^2-9, and v=ds/dt (which is certainly true), then
\[s=(\frac{ ds }{ dt })^{2}-9.\].
Since the derivative is squared, this is a NON-LINEAR differential equation. Agreed?
I'm well equipped to solve first order linear d. e.'s, but not non-linear ones. Have you any experience with solving non-linear d. e.'s?

Answer 18

I see in your notes that your teacher has mentioned the relationship
\[v ^{2}=v _{0}^{2}+2as.\] I've certainly used that before, in cases where the acceleratin is constant, but am wondering whether it applies when the acceleration is NOT constant.

I hope these questions and suggestions are of some help to you. I'd be interested in knowing your thoughts after you've had some time to review what I've written and to reflect upon it.

Answer 19

the other forms
i forgot some of it mathdale

Answer 20

Sorry, Josh, I'm not sure I understand what you're trying to say. What "other forms"?

Answer 21

other forms aside from linear d.e

Answer 22

I have no recent experience in solving non-linear differential equations; have y ou any experience? No? OK.
Do you have a classmate with whom you could share ideas regarding the solution of this problem?

Answer 23

It seems to me that if we knew how to solve nonlinear differential equations, we'd quickly have a solution to \[s=\left( ds/dt \right)^{2}-9.\]

Answer 24

This relationship does relate s and t, as was required. But it'd be so much nicer were we able to solve that nonlinear d. e.
Josh, happy to work with you. Thought provoking problem. Sorry I'm not able to do any more beyond this point. If you have other problems to work on, submit some either through OpenStudy.com or through a private message to me. Good luck!

Answer 25

....ok tnx mathmale!!! i really appreciate it

Answer 26

Happy to do this! Again, I wish so much I were able to help you reach a definitive answer. Bye for now!

Answer 27

ok tnx bro