Answer:
(a) λ = 4136 nm → infrared
(b) λ = 413.6 nm → visible light
(c) λ = 41.36 nm → ultraviolet
Explanation:
The wavelength of infrared is on the range of 700 nm to 1000000 nm
The wavelength of visible light is between 400 nm and 700 nm
The wavelength of ultraviolet ray on the range of 10 nm to 400 nm
The wavelength of photon is given by;
E = hf
f is the frequency of the wave = c / λ
Where;
c is the speed of light = 3 x 10⁸ m/s
h is Planck's constant = 6.626 x 10⁻³⁴ J/s
(a) 0.3 eV = 0.3 x 1.602 x 10⁻¹⁹ J
λ = 4136 x 10⁻⁹ m
λ = 4136 nm → infrared
(b) 3.0 eV
λ = 413.6 x 10⁻⁹ m
λ = 413.6 nm →visible light
(c) 30 eV
λ = 41.36 x 10⁻⁹ m
λ = 41.36 nm →ultraviolet
If this metal is replaced with a metal having a higher work function, yellow light may be able to remove electrons but the electrons ejected will have less kinetic energy and the required stopping potential would be less. So in order to remove electrons( with more kinetic energy), we need to use light having even more shorter wavelength than yellow light because light with shorter wavelength possesses more energy and the electrons will eject with greater kinetic energy. Hence BLUE light should be used for better results cuz its wavelength is less than yellow light. Hope it helps.
They will say hamsters are related to birds lol
To develop this problem it is necessary to apply the concepts related to the calculation of the Force through density and volume as well as the ideal gas law.
By definition, force can be expelled as
F = ma
Where,
m = mass
a = Acceleration
At the same time the mass can be defined as function of density and Volume
Therefore if we do a sum in the spherical balloon we have,
Where,
= Force by weight of balloon
= Force by weight of helium gas
= Buoyant force
Re-arrange to find
Our values are given as,
Replacing the values we have,
Applying the ideal gas law we have finally that
Where,
P = Pressure
Density
M_0 Molar mass (0.004Kg/mol for helium)
R= Gas constant
T = Temperature
Substituting
Therefore the absolute pressure of the helium gas is