A community for students.
Here's the question you clicked on:
 0 viewing
Knowledge
 10 months ago
can someone help me on the question 2C10. It
is Unit 2 Exercises Problem Set 4. The question can be found at this link
http://ocw.mit.edu/courses/mathematics/1801scsinglevariablecalculusfall2010/unit2applicationsofdifferentiation/partboptimizationrelatedratesandnewtonsmethod/problemset4/MIT18_01SC_pset2prb.pdf.
I have problems coming up with the basic function to represent time.
Knowledge
 10 months ago
can someone help me on the question 2C10. It is Unit 2 Exercises Problem Set 4. The question can be found at this link http://ocw.mit.edu/courses/mathematics/1801scsinglevariablecalculusfall2010/unit2applicationsofdifferentiation/partboptimizationrelatedratesandnewtonsmethod/problemset4/MIT18_01SC_pset2prb.pdf. I have problems coming up with the basic function to represent time.

This Question is Open

phi
 10 months ago
Best ResponseYou've already chosen the best response.0The solution is posted... However, they did manage to confuse the sin with the cosine The relation you will find for this problem is \[ \frac{\cos \alpha}{\cos{\beta}} = \frac{5}{2} \] In Snell's Law, they define the angle with respect to the surface normal, i.e. 90\(\alpha\)), and you end up with sin (rather than cos) as for setting up the equations, the most basic idea is rate * time = distance and time= distance/rate Use Pythagoras to find the length of the hypotenuse of the triangle (from A to the water line). Divide this distance by the speed = 5 m/s Call this t1 Do the same for the other triangle, but use speed = 2 m/s, and call this t2 Total time is t1+t2, and it is a function of x (distance from pt P, where you dive into the water): \[ T(x) = t_1(x) + t_2(x) \] Take the derivative with respect to x, and set equal to zero, to find the critical point: \[\frac{d}{dx} T(x) = 0 \\\frac{d}{dx}t_1(x) + \frac{d}{dx}t_2(x) = 0 \]
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.