A totally absorbing surface having an area of 7.7 cm2 faces a ...

[ghost!]

A totally absorbing surface having an area of 7.7 cm2 faces a small source of sinusoidal electromagnetic radiation that is 2.4 m away.
 
  At the surface, the electric field amplitude of the radiation is 84 V/m. (c = 3.00  108 m/s, 0 = 4  10-7 T  m/A, 0 = 8.85  10-12 C2/N  m2)
  (a) What is the radiation pressure exerted on the surface?
  (b) What is the total power output of the source, if it is assumed to radiate uniformly in all directions?

Question 2

In a thermodynamic process involving 7.8 moles of an ideal gas, the gas is at an initial temperature of 24C and has an initial volume of 0.040 m3.
 
  The gas expands adiabatically to a volume of 0.080 m3. For this gas, CV = 12.27 J/mol  K, and the ideal gas constant is R = 8.314 J/mol  K. Calculate the work done by the gas during this expansion.

[shewald78]

Answer to Question 1

(a) 0.031 Pa (b) 680 W

Answer to Question 2

11 kJ

[ghost!]

Thanks for the timely response, appreciate it

[isabelt_18]

Gracias!