Answer:
Thermal Power = 460W
Explanation:
From Stephan-Boltzmann Law Formula;
P = єσT⁴A
Where,
P = Radiation energy
σ = Stefan-Boltzmann Constant
T = absolute temperature in Kelvin
є = Emissivity of the material.
A=Area of the emitting body
Now, σ = 5.67 x 10^(-8)
є = 0.6
Temperature = 30°C and coverting to kelvin = 30 + 273 = 303K
Area ; since we are to consider the sides of the human body as 2m and 0.8m,thus area = 2 x 0.8 = 1.6
Thus thermal power = 0.6 x 5.67 x 10^(-8) x303⁴ x 1.6 = 458. 8W
Normally, we approximate to the nearest 10W. Thus, thermal power is approximately 460W
<span>The visible light has wavelength in the range 400 - 700 nano-meters. The wavelengths longer than visible light are: 1-Infrared waves (used in ringtone/mobile waves)2-microwaves - used to heat and cook food. 3- Radio waves - used in communication purposes.</span>
Answer:
options A and C
Explanation:
Since, the spheres are of same size and rotational speed of the sphere are not dependent on their masses. So, both the sphere will reach the bottom of the at the same time with the same speed. But their kinetic energies are different.
So, options A and C are correct.
Answer:
The nucleus has an overall positive charge as it contains the protons. Every atom has no overall charge (neutral). This is because they contain equal numbers of positive protons and negative electrons. These opposite charges cancel each other out making the atom neutral.
Answer:
Work done against gravity will be
W = Mgℓ
Explanation:
Work done to raise the mass from ground to given height is against gravity
So here work done is given by the formula
here we know that
it is the force due to gravity which is also known as weight
so here distance moved by the object is given as
d = ℓ
now work done is given as
W = Mg ℓ
