Answer:
The temperature is
Explanation:
From the question ewe are told that
The rate of heat transferred is
The surface area is
The emissivity of its surface is
Generally, the rate of heat transfer is mathematically represented as
=>
where is the Boltzmann constant with value
substituting value
Answer:
B. Steam burns the skin worse than hot water because the latent heat of vaporization is released as well.
Explanation:
It is given that both steam and the boiling water when in contact with the skin cools down from 100 to 34 degrees Celsius.
For any substance of mass m, the heat required to change the temperature by is
(S.I. unit = Joules).
where C, the specific heat capacity is the same and a constant for both the condensed steam and the boiling water.
But, there is a "hidden" energy (heat) released by the steam called latent heat
(given by mL, L = specific latent heat) which allows the phase transition (gas to liquid). While both of them are at the same temperature, their energy (heat) is different, which is why steam causes burns worse than boiling water
Answer:
Energy = 7.83 x 10⁻¹⁹ J
Energy = 6.63 x 10⁻¹⁹ J
Explanation:
The energy of a photon in terms of wavelength can be calculated by the following formula:
where,
h = Plank's Constant = 6.63 x 10⁻³⁴ Js
c = speed of light = 3 x 10⁸ m/s
λ = wavelength of light
Now, for λ = 254 nm = 2.54 x 10⁻⁷ m:
<u>Energy = 7.83 x 10⁻¹⁹ J</u>
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Now, for λ = 300 nm = 3 x 10⁻⁷ m:
<u>Energy = 6.63 x 10⁻¹⁹ J</u>