In the photoelectric effect, the energy of the incoming photon (E=hf) is used in part to extract the photoelectron from the metal (work function) and the rest is converted into kinetic energy of the photoelectron:

where
h is the Planck constant
f is the frequency of the incident light

is the work function of the material
K is the kinetic energy of the photoelectron.
The photoelectron generally loses part of its kinetic energy inside the material; however, we are interested in its maximum kinetic energy, that is the one the electron has when it doesn't lose energy, so we can rewrite the previous equation as

The work function is (in Joule)

and using the data of the problem, we find the maximum kinetic energy of the photoelectrons
Answer:
Explanation:
a )
Pressure on the bottom
= hdg
= 2.5 x 820 x 9.8
= 20090 N / m²
b )
force = area x pressure
= 20090 x 10 x 6 N
= 1205400 N
c )
Force on 10m x 2.5 m face
center of gravity of the tank will lie at height 2 .5 / 2 = 1.25 m
Pressure = hdg
= 1.25 x 820 x 9.8
= 10045 N/m²
force = pressure x area
= 10045 x 10 x 2.5
= 251125 N .
Explanation:
We need to calculate the centripetal force:
Fc = W + F
With Fc being the centripetal force, W the weight of the boy, F the centrifugal force (apparent).
We know that we can calculate the apparent centrifugal force thank to the formula:
F = (m·v²)/r = 204N
So we can write:
Fc = W + F = 445N + 204N = 649N
When gas hydrates are brought to the surface, they evaporate quickly. This would be the biggest, current disadvantage to using gas hydrates as a form of energy.