A double-slit experiment uses coherent light of wavelength 633 nm ...

[lbcchick]

A double-slit experiment uses coherent light of wavelength 633 nm with a slit separation of 0.100 mm and a screen placed 2.0 m away.
 
  (a) How wide on the screen is the central bright fringe?
  (b) What is the distance on the screen between first-order and second-order bright fringes?
  (c) What is the angular separation (in radians) between the central maximum and the first-order maximum?

Question 2

A piece of iron of mass 0.12 kg is taken from an oven where its temperature is 336C and quickly placed in an insulated copper can that contains 0.20 kg of water.
 
  The copper can has mass 0.50 kg, and it and the water in it are originally at a temperature of 20C. Calculate the final temperature of the system, assuming no thermal energy is transferred to the surroundings. Use the following specific heats: 4190J/kg  C (water), 470 J/kg  C (iron), and 390 J/kg  C (copper).

[voltaire123]

Answer to Question 1

(a) 1.3 cm (b) 1.3 cm (c) 6.33 mrad

Answer to Question 2

36C

[lbcchick]

Wow, this really help

[upturnedfurball]

Great answer, keep it coming