Recent content by teddyayalew

I just got confused after watching this video : http://www.khanacademy.org/science/physics/v/work-and-energy--part-2 It starts from 2:55 where he says he raises the object by applying an upward force of mg.

If the force applied on ab object due to gravity is -mg why is applying a force of mg give upward raise the object if the two forces are equal and opposite in direction. I would think the object would remain still until you apply a force greater than mg.

It doesn't say which space. It was just a true or false statement, but I know that the entries of the vectors can be from the complex space. And it doesn't tell me which definition of the inner product but I believe it is the standard inner product.

Homework Statement An inner product is linear in both components. Homework Equations <x,y> = <conjugate(y),conjugate(x)> <x+y,z> = <x,z> +<y,z> The Attempt at a Solution I thought it was true . It is obvious that it is linear for the first component by definition Attempt to show...

Homework Statement http://i43.tinypic.com/fymy3l.jpg question 22.4 (a) Homework Equations The Attempt at a Solution xk=(xp-1)m = (xp-1-1)(1 + xp-1 +x2(p-1) +...+x(m-1)(p-1)) I know that xp-1-1 = 0 mod p has p-1 solutions but I can't make anything from the geometric sum...

Ahh I see! Thank you for your help.

I see. So if p=2 then I know the sum is : 1 + 1 = 2, which is congruent to 0 mod 2 as well. Thank you both for you help!

Homework Statement http://i44.tinypic.com/33z5js3.jpg It is part b Homework Equations ae = 1 (mod m) a(psi(m)) = 1 (mod m) eu - psi(m)v = gcd(e, psi(m)) = g The Attempt at a Solution I know that eu = g + psi(m)v So then a(eu) = ag + psi(m)= ag*apsi(m) = ag (mod m) from...

Mark, I am sorry I was not clear, when I say p I mean a prime number.

Homework Statement What is the value of 1 + 2 + 3 +...+ (p-1)(mod p)? Homework Equations p = 0 (mod p) p-1 = -1 (mod p) 1 + 2 + 3 + ...+n = n(n+1)/2 The Attempt at a Solution I know 1 + 2 + 3 +...+ (p-1) = (p-1)(p)/2 I worked the problem, but i don't know if i am correct...

Thank you for telling me that. Now I understand the problem!

Ok so instead of finding two ways to represent the initial distance of boat two from boat 1(the origin) I used boat 1 as the fram of reference but I still ended up getting theta = arcsin( (v1 + v2)/v0) Here is my diagram : http://i44.tinypic.com/ndk0fa.jpg

Thank you cepheid I was able to solve the problem.

Homework Statement " A body moving with constant acceleration travels consecutively over two equal 10m segments of its path S. Find the acceleration "a" of the body and its speed v(not) at the start of the first segment, if the first segment is traversed in t(1) = 1.06 seconds and the second...

Homework Statement A right-angle is drawn on a sheet of paper. A ruler , which always remains perpendicular to the bisectrix of this angle moves over the paper with a speed 10cm/sec. The ends of the ruler intersect the sides of the angle. What are the speeds along the sides of the angle of...