Recent content by tebes

Thank you. If I use 3 x 10 ^ 8 m/s as c, I would obtain zero. But If I use c = 299 792 458 m / s, my answer wouldn't be trivial. Does it mean anything physically ?

Homework Statement In the inertial system S, an event is observed to take place at point A on the x-axis and 10^-6 seconds later another event takes place at point B , 900 m further down. Find the magnitude and direction of velocity of S' with respect to S in which these two events appear...

Homework Statement A hollow sphere of radius 0.150 m, with rotational inertia I = 0.0513 kg·m2 about a line through its center of mass, rolls without slipping up a surface inclined at 25.3° to the horizontal. At a certain initial position, the sphere's total kinetic energy is 54.0 J. (a) How...

You are right. We need to exclude the translation.

ok . i ll try it.

I found moment of inertia using parallel-axis theorem. Then, I used the conservation of energy to solve for angular velocity. But I still got it wrong. I = Icom + MH^2 solve for I. Then, 1/2 mv^2 + 1/2 Iw^2 = mgh m(wr)^2 + Iw^2 = 2mgh w^2 = ( 2mgh) / ( I + mr^2) w = [( 2mgh) /...

Homework Statement A uniform cylinder of radius 12 cm and mass 25 kg is mounted so as to rotate freely about a horizontal axis that is parallel to and 6.6 cm from the central longitudinal axis of the cylinder. If the cylinder is released from rest with its central longitudinal axis at the...

"I see that, but you still might be opening the file more than you need to. I don't think that you need to open the file in main() at all, since you are opening it several times in your option function." Reply: I was requested to do that , by my professor. ^.^ I am sorry for ambiguousness ...

Thank you for you suggestion. Those tips really helpful. I'm still a beginner. Reply 1 : I agree with you. Those are really dumb variables. I apologize for giving trouble to you or whoever who read this codes. Reply 2 : You are right. Thank you so much. Reply 3 : The reason I open...

Homework Statement How do I retreat the last entered data from .txt file ? #include <iostream> #include <fstream> #include <string> #include <cstdlib> using namespace std; void menu(int *); void option(fstream &, int *); int main() { int a, p; while(a== 1||2||3||4||5 )...

Homework Statement a frictionless roller coaster car of mass m = 954 kg tops the first hill with speed v0 = 24.2 m/s at height h = 30.8 m. How much work does the gravitational force do on the car from that point to (a) point A. (same height) Homework Equations The Attempt at a...

Homework Statement After I typed in the name, and tested it by running " lookup " under "option". But the "name:" showed nothing. #include <iostream> #include <cstring> #include <cstdlib> using namespace std; const int name_length = 20; struct student { int idnum; char...

Sorry, I didn't know that because PE is the material in next chapter. But I'll read the chapter in advance.

Sorry, there is something still baffle me. May I know why there is no negative sign in front of 1/2kxf^2 ? according to formula, 1/2k(xi^2-xf^2), when xi=0, then formula would be - 1/2kxf^2.

For V, I obtained 3.2 m/s. Then, substituted into P=FV. P= Fs(3.2)= - 148.608 W but the answer is wrong.