Calculus help

UKGrad93

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Jun 20, 2007
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UKgrad93 had the general gist of the solution, just didn't do the math correctly as he pointed out. It is a pretty basic calculus concept, that of limits. As numbers are plugged into a function, the sum of all the answers approaches some number - that number is the limit.

For this problem, when dropped the ball falls 2 m. On the first bounce it returns 3/4 of the original height or 1.5 m. Then descends the 1.5 m to the second bounce. It would then reach a height of 1.125 m, etc. Each bounce gets lower and lower until, on the 1,000th bounce or 1,000,0000th bounce, the height it reaches is a small fraction of a meter. Hence, the sum APPROACHES 14 total meters but would never, in theory, actually reach it. In theory, the ball would never stop bouncing even a miniscule fraction of a meter. Hence the concept of limits. The sum will never go above 14 in this example and will only approach 14 no matter how many bounces you want to calculate.

Having taken 4 semesters of calculus and spent almost 10 years as an electrical engineer in a plant, I can tell you I have NEVER used it since college. If I had ever been in design, I most likely would have used it at some point. Now, that I'm in financial planning, I use basic finance and personal finance concepts every day. So, why are engineers made to take so much damn calculus?
I think it mostly provides you with insight on how to approach certain problems. Algebra is probably used more. Usually have 2 or 3 known values and 1 unknown value that you need to solve for. I would also guess that most engineering courses are calculus based, maybe not so much the actual work.

I needed calculus to get through physics courses. I needed the physics background to do my job, but I use algebra mostly. I've had a few things that really needed calculus though. I should take a refresher course on it.
 
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d2atTech

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I'm just here to ask, how can school's give multiple classes of calculus, which maybe 3% of the class will use.. while ZERO classes of Personal Finance are offered, which EVERYONE could use?

Tell your kid to just cheat his way through this useless class (unless he aspires to go into Science/engineering) and focus his efforts on something else.

because not learning calculus has no consequences, while not learning finance in school makes it your teacher's fault if you go broke
 
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Kooky Kats

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Ok my little burros, you need a ticket to see the show...

It's a piece of cake, upside down.
 

BankerCat12

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Took Calculus at UK. Didn't care for it but much easier than Geometry in HS. I hated that class. That protractor was always stabbing the ish out of me.
 

MWes11

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Its a geometric series.

1 bounce = 2 m

2 bounce = 2(3/4) + 2(3/4) = 3 m

3 bounce = 2(3/4)(3/4) + 2(3/4)(3/4) 2.25 m

N bounce = 2h (3/4)^n

Total = 2 + Sum of [20 *(3/4)^n] from zero to infinity

(copy & paste from equation writer doesn't work)

As n gets bigger, the term that you are adding gets smaller and smaller, eventually it approaches zero.

2 + [(2*2) / (1-(3/4)] = 18 m
 
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Mar 13, 2004
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It's a geometric series: https://en.wikipedia.org/wiki/Geometric_series#Formula

It's going to travel each distance twice (up and down) except the first, which it will only travel once. So you're multiplying 4 (2 up, two down) time the infinite series 1+3/4+(3/4)^2.... and then subtracting 2 since there was no "up" on the first leg.

You solve the infinite series with the formula a/(1-r) where a is the first term (4) and r is the ratio (3/4) so you get 4/(1-3/4) which is 16, subtract the 2, the answer is 14.
 
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BBUK

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Dang, and I have to take differential Calculus class to qualify as a scientist. (Just a work thing, I have been doing the job already.) I'd like to take it online if I can find a joint. Disheartening to say the least...
 

august-west

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I, personally, would pay big money for a ball that would never quit bouncing. Every night I would sit around, drink in hand, and watch my never ending bouncing ball. Well, until I got bored with it and then I would try to use calculus to determine the amount of bounces to how many drinks I needed to get drunk as related to the height of each bounce. Or something like that.
 

BBUK

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I, personally, would pay big money for a ball that would never quit bouncing. Every night I would sit around, drink in hand, and watch my never ending bouncing ball. Well, until I got bored with it and then I would try to use calculus to determine the amount of bounces to how many drinks I needed to get drunk as related to the height of each bounce. Or something like that.


I have some flubber available for a price....I'll make you a good deal.