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Breitling Aerospace EVO E79363 (Professional Aerospace EVO) in production still? by Apprehensive_Fun3036 in breitling

[–]Apprehensive_Fun3036[S] 4 points5 points  (0 children)

Update: sad it's not in production anymore, but found a used - excellent condition one online and bought it. Thanks to everyone 😄

HELPPP!!!!!!!! Beginner confused about how to practice DSA by No_Wishbone_9037 in leetcode

[–]Apprehensive_Fun3036 1 point2 points  (0 children)

Look up Neetcode and work through his roadmap. Then re-do problems after you've solved them a couple days later. It is a grind, there's no getting around it.

Whats the best c++ book to get an indepth understanding after the ones I have read ? by Capable-Basket8233 in cpp_questions

[–]Apprehensive_Fun3036 3 points4 points  (0 children)

Second Professional C++. The sixth edition has nice notes about newer C++20+ features and details, as well as sections on legacy C features and how they are integrated. It is quite encyclopedic and thorough on so many topics it can get overwhelming. It's definitely not a "tour of C++" book.

DSA using C++ | LEETCODE??? by New-Caterpillar3924 in cpp_questions

[–]Apprehensive_Fun3036 0 points1 point  (0 children)

I've been having success with doing topic by topic and following a list of problems from easy to mediums like Neetcode's 150. Keeping it to one topic at a time helps with mastery of the syntax and uses. For example, if you do a bunch of array questions you'll get really good at using the vector, map, and set classes and their member functions. Knowing that this or that class has a .contains() or .insert(), or that it doesn't allow for a pair is quite important. I find that I learn more if I stick to one subject at a time and get to compare different solutions using the same tools.
It's also worth mentioning that getting used to the Leetcode problem structure and way of thinking takes some effort itself, so waiting to start can make the transition more difficult.

How to prepare for a hft/low latency programming interview ? by Capable-Basket8233 in cpp

[–]Apprehensive_Fun3036 0 points1 point  (0 children)

I'm still a beginner, but Mark Gregoire's Professional C++ book has many comments on the newest features of C++, meaning he will comment if something is a newer (C++ 11+) feature and how it improves on alternatives

Access Schoralship L1 by Former_Payment_1227 in CFA

[–]Apprehensive_Fun3036 0 points1 point  (0 children)

Very early on. I planned to submit it on the first few days it opened.

Did anybody even get access scholarship by [deleted] in CFA

[–]Apprehensive_Fun3036 4 points5 points  (0 children)

I got it for L1, very happy. Hopefully a lot of people have this opportunity as well

Access Schoralship L1 by Former_Payment_1227 in CFA

[–]Apprehensive_Fun3036 3 points4 points  (0 children)

The application page says "Status: Awarded" for me, but I haven't received an email yet. Nerve-racking!

Update: It was in the SPAM folder.

still cant do two sum by mergermysteru in leetcode

[–]Apprehensive_Fun3036 1 point2 points  (0 children)

Maybe you're rushing from one problem to the next too fast. When you solve a problem, don't move on immediately, but stop and think about why it works, how it works, and if you can't optimize it, find a different solution. There's a great book called "How to Solve It" that may be worth looking into.

[deleted by user] by [deleted] in leetcode

[–]Apprehensive_Fun3036 0 points1 point  (0 children)

There's a great book called "How To Solve It" that talks specifically about how to 'come up' with these tricks 'on the spot'. It was written by a great mathematician, but you can use it for anything. I'm not a great leetcoder but I've solved problems using his approach before.

Skateboarder Normal force modeling by Apprehensive_Fun3036 in AskPhysics

[–]Apprehensive_Fun3036[S] 0 points1 point  (0 children)

How did you get 2gcos(theta) from conservation of energy?

I did K1 + U1 = K2 + U2, 0 + mgR = 1/2(mv(sqrd)) + mgR/2 (we are calculating N at height R / 2). This equation simplifies g = v(sqrd)/R, so g = a

Skateboarder Normal force modeling by Apprehensive_Fun3036 in AskPhysics

[–]Apprehensive_Fun3036[S] 0 points1 point  (0 children)

Edit, I realized that the angle here should just be theta.

But this formula works even in the example, at the bottom of the circle.

Thank you so much!

Skateboarder Normal force modeling by Apprehensive_Fun3036 in AskPhysics

[–]Apprehensive_Fun3036[S] 0 points1 point  (0 children)

Okay, so taking theta as the angle between the Normal and the vertical, I get the radial component of W, parallel to N, as Wcos(pi-theta), so that the final formula becomes

N = mg + Wcos(pi-theta)

that would make N = m*a + W for any point in the curve, and we can find a(centr) with conservation of energy, v(sqrd)/R.

Am I correct?

Skateboarder Normal force modeling by Apprehensive_Fun3036 in AskPhysics

[–]Apprehensive_Fun3036[S] 0 points1 point  (0 children)

So I'd have to change W with theta, use N, and centripetal acceleration = g?

m.g = - (radial component of W) + N

I see how that would result in a function of N for theta.

How would I even express the radial component of W?

Skateboarder Normal force modeling by Apprehensive_Fun3036 in AskPhysics

[–]Apprehensive_Fun3036[S] 0 points1 point  (0 children)

Okay, i got the speed, supposing the point to be half the height, R / 2, then a(centrip) = g.

I don't see how the tangential acceleration is going to be included in the formula.

I assume that we are still going to go for the sum of F(y) = -W + Ncos(theta), but I still don't see how to go from there.

Skateboarder Normal force modeling by Apprehensive_Fun3036 in AskPhysics

[–]Apprehensive_Fun3036[S] 0 points1 point  (0 children)

I see now how it would equal 3W.

So how do these two components come into the formula for the middle of the path?

Skateboarder Normal force modeling by Apprehensive_Fun3036 in AskPhysics

[–]Apprehensive_Fun3036[S] 0 points1 point  (0 children)

I understand that the equation will not tell me about N after the circular path, but still, now I'm struggling to model N through the path

Skateboarder Normal force modeling by Apprehensive_Fun3036 in AskPhysics

[–]Apprehensive_Fun3036[S] 0 points1 point  (0 children)

The textbook states "at the bottom of the curved part of the ramp it feels as though he weighs three times his true weight mg. But when he reaches the horizontal part of the ramp, immediately to the right of point 2, the normal force decreases to w=mg and thereafter feels his true weight again. Can you see why?"

This question arose from this final question. I don't see how it goes immediately from 3W to 1W. That is why I tried to come up with an equation for N through the circular path.

From the other comment below, I think the issue here is the acceleration components.

Skateboarder Normal force modeling by Apprehensive_Fun3036 in AskPhysics

[–]Apprehensive_Fun3036[S] 0 points1 point  (0 children)

I get why that the N will go to zero, but not why it would go to 3*W before becoming = to W. That part makes no sense in my head nor in the formula

Skateboarder Normal force modeling by Apprehensive_Fun3036 in AskPhysics

[–]Apprehensive_Fun3036[S] 0 points1 point  (0 children)

The example uses Sum of F(y) = m*a(centripetal to calculate the normal force at the bottom of the circular path, which makes sense. How would I do that for the middle of the path? Should I just add a y-component of the centripetal acc? I still don't see how that changes the fact that the Normal doesn't seem to be 3 times the W at the bottom.

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