Gamma rays are photons with very high energy. How many ...

[torybrooks]

Gamma rays are photons with very high energy. How many visible-light photons with a wavelength of 500 nm would you need to match the energy of a gamma-ray photon with energy 4.1  10-13 J? (h = 6.626  10-34 J  s, c = 3.00  108 m/s)
 
  A) 1.0  106
  B) 1.4  108
  C) 6.2  109
  D) 3.9  103

Question 2

Two experimental runs are performed to determine the calorimetric properties of an alcohol that has a melting point of -10C.
 
  In the first run, a 200-g cube of frozen alcohol, at the melting point, is added to 300 g of water at 20C in a styrofoam container. When thermal equilibrium is reached, the alcohol-water solution is at a temperature of 5.0C. In the second run, an identical cube of alcohol is added to 500 g of water at 20C and the temperature at thermal equilibrium is 10C. The specific heat of water is 4190 J/kgK. Assume that no heat is exchanged with the styrofoam container and with the surroundings. The heat of fusion of the alcohol is closest to
  A) 5.5  104 J/kg
  B) 7.1  104 J/kg
  C) 7.9  104 J/kg
  D) 6.3  104 J/kg
  E) 8.7  104 J/kg

[flannelavenger]

Answer to Question 1

A

Answer to Question 2

D