Lamborghini Aventador RPM Query

[Thangavel]

I am posting this as new topic for more visibility.
I am Ph.D. Scholar in a university in Guindy so you might now know where I am.
I came across this expression for Lamborghini Aventador rpm during my research. Since all of you seem to be experts can you please explain why this is so complicated?



I have also posted in other forums though they are still to approve it. In case you are member of other forums, you may answer there also
Thank you in advance.

 

[carcommentor]

This seems to be a prank! The formula is not complicated at all. The first expression is actually zero and the denominator of second expression is nothing but 2x Pi x radius !
I will try to explain. In the first expression, x^3 is odd function and Cos(x/2) & Square Root (4-x^2) are even functions. We all know that the product of odd and even function is always odd. An integral of an odd function over symmetric interval (in this case 2 to -2) is ALWAYS zero! So the first expression is actually just zero.
Coming to the denominator of next integral, note Square root (4-x^2). We know that a unit circle can be represented by x^2+y^2=1, so y= Square root (1-x^2), which means the integral of Square root (4-x^2) is just area of semicircle with radius of 2! And what is the area of this semi-circle? Pi x (2^2)/2 . Half of this (1/2) is just Pi ! so denominator turns out to be just 2 x Pi x (0.4826/2) ! the entire formula is just 0 + (5816.67)/2 x Pi x (0.4826/2) = 3836.52 rpm

The formula of revolutions per minute = speed in meters per minute / circumference in meters

, So the speed of Lamborghini is 5816.67 Meter per minute (about 349 km / hr ). The circumference = 2 Pi (0.4826 /2) = 1.51613. I think 0.4826 is diameter in meters (about 19 Inches).
So at the end of it all the above complicated expression is nothing but prank for simple formula: revolutions per minute = speed in meters per minute / circumference in meters !

P.S : The expressions reminded me of reading similar prank (but not this automobile related formula) in some stackexchange maths forum. Hope you didn't fall for the prank !

 

[Thangavel]

Thank you so much .I love your explanation and very satisfied with the answer. I thought this was serious formula and not a prank. Thank you for clarifying. In other forums they were ridiculing this as a troll post! This is the only forum which was so welcoming. Thanks.

 

[bhvm]

Thangavel,
Welcome to the forums.

You have posted in many other forums before. I was going to invite you here (TAI). Thankfully you are here. TAI is a humble forum where senior members are interested in Serious Gyaan rather than Ridiculing others (esp newbies as you have already seen in other forums!)

Welcome once again, Do share about your cars/Travel and have a pleasant stay!

 

[Thangavel]

Thangavel,
Welcome to the forums.

You have posted in many other forums before. I was going to invite you here (TAI). Thankfully you are here. TAI is a humble forum where senior members are interested in Serious Gyaan rather than Ridiculing others (esp newbies as you have already seen in other forums!)

Welcome once again, Do share about your cars/Travel and have a pleasant stay!

Thank you for the warm welcome. I can certainly see that the quality of forum members and moderators here are exemplary !
I have replied to every snide remark in the other forum politely, but their moderator hasn’t bothered to approve any of those replies so all replies are pending. It’s obvious that the moderator doesn’t want to embarrass their long term posters !
I will definitely share my travelogues.