Recent content by jazzchan

yes...my question is to find how much 25 degree water should be used... would u tell me more ?? thanks...

is it mean the Q of temperature from 75 to 60^c is equal to the Q of 25 to 60^C ?? thank

Dear all Here is a question i need to help Can I know how much water at 25^C to put into a water at 75^C and then the mixture is 60^C ?? thanks and best regards Jazz

I know that it is necessary t ofind the min Ixx or Iyy for second moment of the area. I think I should use the whole I-section beam to for area calculation. thanks a lot

Dear FredGarvin in your last sentence, the column means the area only base part of the I-Beam ? regards, jazz

Dears, the detail question is as follow: An I-section joist has total height 160 mm, total width 120 mm, and the thickness throughout of 5 mm. It is 4m long. It made of steed with yield stress =280MN/m2 and E=210GN/m2. a) when loaded only in tension along its axis, what tensile load could...

Dear all, I have a question are as follows: It is a I-Section joist, the question is find the compressive load could it take with ball-jointed ends. i want to know what is ball-jointed ends ?? is it mean the base of the I-Section joist ?? if yes, what is the surface area i need to...

I have a problem as follows: A rugby player, mass 120 kg is running due south at 6 m/s. He is tacked by an opponent, mass 90 kg, due east at 8 m/s. Calculate the combined speed of the joined players immediately after the tacke. I assume that m1*u1 + m2*u2 = (m1+m2)V is it right ...

thanks a lot !

Dear Doc Al what is meaning of repel ?? if there is two postive charge at the X axis, one is 5C at x = 0, other is 6C at x = 40, so what is the force direction ?? positve or negative ?? thanks jazz

Dear all... i have a question about coulomb's law as follows: if there are three point charges are placed at the x-axis, first is +C, second is -C and the last one also is -C. How could i know the direction of the force at the second and third one ?? best regards. jazz

The question is: A hydrogen atom absorbs a photon and makes a transition from a 3d level to a 4f level. What is the wavelength of the absorbed photon ? As i know 3d is n = 3, 4f is n = 4 and wavelength = hc/delta E so the deltaE is E4 - E3 or E3 - E4 ?? thanks..

can i assume the equation is: K.E = hf - work function = 0 ?? thanks

Dear all The question is : A certain material has a work function of 0.4eV. What is the energy of a single photon of electromagnetic radiation at the threshold frequency for liberation of photoelectrons? Would u give me some hint how to find the threshold frequency at first ?? thanks...

Dear all, the question is ... Two flat glass plates touch at one edge and are separated at the other edge by a spacer. Using vertical viewing and light is 589 nm(wavelength), five dark fringes(D) are obtained from edge to edge. What is the thickness of the spacer ?? i know that the...