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How many photons are required to heat 200 mL of coffee from 25°C to 61°C?

a) 0.0013
b) 0.0028
c) 0.0035
d) 0.0042

User Zcourts
by
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1 Answer

5 votes

Final answer:

To heat the coffee, we need to calculate the energy of the coffee using Q = mcΔT. Then we calculate the energy of a single microwave photon using E = hf. Finally, we calculate the number of photons required using N = Q / E. The correct answer is d) 0.0042.

Step-by-step explanation:

To calculate the number of photons required to heat the coffee, we need to use the equation Q = mcΔT, where Q is the heat, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature.
The heat required to heat the coffee can be calculated as Q = (200g) * (4.18J/g·°C) * (61°C - 25°C).

Next, we need to calculate the energy of a single microwave photon using the equation E = hf, where E is the energy, h is Planck's constant (6.63 x 10^-34 J·s), and f is the frequency.

Finally, we can calculate the number of photons required using the equation N = Q / E.

Plugging in the values, we get: N = (200g) * (4.18J/g·°C) * (61°C - 25°C) / (6.63 x 10^-34 J·s * 3 x 10^8 s^-1).

Simplifying the equation gives us: N ≈ 8.28 x 10^28 photons.

Therefore, the correct option is d) 0.0042.

User Liuliu
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8.4k points