Acontainer with 0.485 l of water is placed into microwave and is then radiated with electromagnetic energy that has a wavelength of 14.1 cm. the temperature of the water then rose by 69.9 °c. calculate the number of photons that were absorbed by the water. assume water has a density of 1.00 g·ml–1 and its specific heat is 4.184 j·g–1·°c–1

The number of photons that were absorbed by the water is about:

1.00 × 10²⁹ photons

The term of package of electromagnetic wave radiation energy was first introduced by Max Planck. He termed it with photons with the magnitude is:

E = Energi of A Photon ( Joule )

h = Planck's Constant ( 6.63 × 10⁻³⁴ Js )

f = Frequency of Eletromagnetic Wave ( Hz )

The photoelectric effect is an effect in which electrons are released from the metal surface when illuminated by electromagnetic waves with large enough of radiation energy.

E = Energi of A Photon ( Joule )

m = Mass of an Electron ( kg )

v = Electron Release Speed ( m/s )

Ф = Work Function of Metal ( Joule )

q = Charge of an Electron ( Coulomb )

V = Stopping Potential ( Volt )

Let us now tackle the problem!

Given:

wavelength = λ = 14.1 cm

volume of water = V = 0.485 L

change in temperature = Δt = 69.9 °C

density of water = ρ = 1.00 g/mL = 1.00 kg/L

specific heat capacity of water = c = 4.184 J/g°C = 4184 J/kg°C

speed of light = c = 3 × 10⁸ m/s

Asked:

number of photons = N = ?

Solution:

Grade: High School

Subject: Physics

Chapter: Quantum Physics

0.55x745.7j and a calculator

wavelength divides in half and speed stays the same.