projectile motion with quadratic drag (1 Viewer)

[tywebb]

jim green made this question

then shane scott made this solution

eddie woo made youtubes:

BUT. There is something wrong

Can you see what is wrong?

 

[H.S. Carslaw]

bro they are rizzing up the impossible

 

[tywebb]

yeah in eddie woo's second youtube mxlexrd put this comment "it's not possible to decouple the X and Y components" making solution incorrect

 

[ivanradoszyce]

Find a link to an explanation using Manim.

Projectile Motion with Quadratic Drag.

 

[epicmaths]

Doing some late night browsing. If someone were to teach this topic - should quadratic drag be delved into if at all?

The 2017 Syllabus: (disgusting)
Solve problems involving projectile motion in a resisting (vague much?) medium and under the influence of gravity
which include consideration of the complete motion of a particle projected vertically upwards or at
an angle to the horizontal.


The 2024 Syllabus: Establish and use the equations for acceleration for a projectile moving under the influence of gravity, projected at an angle to the horizontal, and subject to a resistance whose magnitude is proportional to the speed, to solve problems.

The update to the syllabus has given up on quadratic drag, and gives itself permission to ask the question like in 2023...

How safe are we from a non-linear resisted projectiles in the 2024 and 2025 papers?

 

[tywebb]

should quadratic drag be delved into if at all?

Depends on how prepared you are to openly and deliberately defame nesa, textbook authors, and multi-billion-dollar multinational publishers.

I'll give it a go.

As far as projectile motion with quadratic drag is concerned the current syllabus is complete garbage.

The mif and nsm textbook authors are complete amateurs, have no idea what they are talking about - and continued publication of their rubbish is doing a disservice to education in the schools that use their textbooks.

The publishers were warned before publication that their treatment of this is wrong, but arrogance, snobbery, ego, power, money - all got in the way of common sense. Some tried to save them from the ensuing embarrassment, but they reap what they sow, and now deserve to be defamed.

Defamation proceedings however will not commence because their legal teams will simply advise that if it goes to court, the judge will dismiss the case because they chose to publish rubbish and defendants simply called them out on it, as is their democratic right.

If you wish to delve into projectile motion with quadratic drag and do it properly, ask yourself the question how prepared are you to use out-of-syllabus methods more appropriate to this issue like Euler method or Runge-Kutta method

The Cambridge Extension 2 book simply says this: "solutions can only be found in one case, when the resistance is proportional to the velocity."

Perhaps now you understand why nesa has made it clear in the new syllabus that they won't be doing projectile motion with quadratic drag.

 

[tywebb]

And if you are at all tempted to jump on the Jim Green/Bob Aus bandwagon like Eddie Woo and Shane Scott did, don't. Just don't.

 

[tywebb]

like in 2023...

You mean Q14c in the 2023 Extension 2 HSC?

Well that is a very limited question and does not come anywhere close to what mif and nsm try to do with a false analytic solution for the trajectory of the motion.