Answer : The energy of one photon of hydrogen atom is, 
Explanation :
First we have to calculate the wavelength of hydrogen atom.
Using Rydberg's Equation:

Where,
= Wavelength of radiation
= Rydberg's Constant = 10973731.6 m⁻¹
= Higher energy level = 3
= Lower energy level = 2
Putting the values, in above equation, we get:


Now we have to calculate the energy.

where,
h = Planck's constant = 
c = speed of light = 
= wavelength = 
Putting the values, in this formula, we get:


Therefore, the energy of one photon of hydrogen atom is, 
Answer:
Heating water to produce steam which drives a turbine
Explanation:
Generation of electricity in coal-burning power plants and nuclear power plants both involve heating water to produce steam which drives a turbine.
Answer:
Impulse of force = -80 Ns
Explanation:
<u>Given the following data;</u>
Mass = 50kg
Initial velocity = 1.6m/s
Since she glides to a stop, her final velocity equals to zero (0).
Now, we would find the change in velocity.
Substituting into the equation above;
Change in velocity = 0 - 1.6 = 1.6m/s
Substituting into the equation, we have;
<em>Impulse of force = -80 Ns</em>
<em>Therefore, the impulse of the force that stops her is -80 Newton-seconds and it has a negative value because it is working in an opposite direction, thus, bringing her to a stop. </em>
Pressure at a given surface is given as ratio of normal force and area
so here force due to heel of the shoes is given as 80 N
and the area of the heel is given as 16 cm^2
so we can say

here we have
F = 80 N



so pressure at the surface due to its heel will be 5 * 10^4 N/m^2