Answer:
To increase the maximum kinetic energy of electrons to 1.5 eV, it is necessary that ultraviolet radiation of 354 nm falls on the surface.
Explanation:
First, we have to calculate the work function of the element. The maximum kinetic energy as a function of the wavelength is given by:
Here h is the Planck's constant, c is the speed of light, 
is the wavelength of the light and W the work function of the element:
Now, we calculate the wavelength for the new maximum kinetic energy:
This wavelength corresponds to ultraviolet radiation. So, to increase the maximum kinetic energy of electrons to 1.5 eV, it is necessary that ultraviolet radiation of 354 nm falls on the surface.
Answer:
<em>1.187 x 10^8 m/s</em>
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Explanation:
the potential of the electric field V = 40 kV = 40000 V
the charge on an electron e = 1.6 x 10^-19 C
The energy of an accelerated electron in an electric field is given as
E = eV
E = 1.6 x 10^-19 x 40000 = 6.4 x 10^-15 J
This energy is equal to the kinetic energy with which the electron moves, according to the conservation of energy.
The kinetic energy = 
where
m is the mass of the electron = 9.109 x 10^-31
v is the speed of the electron.
Equating the energy, we have
6.4 x 10^-15 = 
6.4 x 10^-15 = 4.55 x 10^-31 
= 1.41 x 10^16
= <em>1.187 x 10^8 m/s</em>
The biological process that directly converts energy from the Sun into chemical energy would be Photosynthesis. It is a process carried out by autotrophic organisms which are predominantly plants and other photosynthetic bacteria.
The two factors are mass and distance between them.
You've listed a lot of data here, in both metric and customary units,
and I'm not even sure it's all needed. Let me try and boil it down:
Pressure on a surface =
(total force on a surface) divided by (area of the surface).
The answer to the question is the pressure expressed in pascals.
There's actually enough information here to answer the question
in 2 different ways. We could ...
-- simply convert (0.03 pound per inch²) to pascals, or
-- go through the whole calculation of force, area, and then their quotient.
To me, converting 0.03 psi to Pa looks easier.
-- 1 pascal = 1 newton / 1 meter²
-- On Earth, 1 kilogram of mass weighs 9.8 Newtons and 2.2 pounds.
From this, we can calculate that
2.2 pounds of force = 9.8 newtons of force.
1 pound = 4.45 newtons
(0.03 pound/inch²) x (4.45 newton/pound) x (1inch/2.54cm)² x (100cm/1m)² =
(0.03 x 4.45 x 1² x 100²) / (2.54² x 1²) newton/meter² = 206.9 Pa .
