Answer:
The shortest de Broglie wavelength for the electrons that are produced as photoelectrons is 0.81 nm
Explanation:
Given;
wavelength of ultraviolet light, λ = 270 nm
work function of the metal, φ = 2.3 eV = 2.3 x 1.602 x 10⁻¹⁹ J = 3.685 x 10⁻¹⁹ J
The energy of the ultraviolet light is given by;
The energy of the incident light is related to kinetic energy of the electron and work function of the metal by the following equation;
E = φ + K.E
K.E = E - φ
K.E = (7.362 x 10⁻¹⁹ J) - (3.685 x 10⁻¹⁹ J )
K.E = 3.677 x 10⁻¹⁹ J
K.E = ¹/₂mv²
mv² = 2K.E
velocity of the electron is given by;
the shortest de Broglie wavelength for the electrons is given by;
Therefore, the shortest de Broglie wavelength for the electrons that are produced as photoelectrons is 0.81 nm
Answer: a) 0.315 (V/L)
Explanation:
From Conservation of angular momentum, we know that
L1 = L2 ,
Therefore MV L/2 = ( Irod + Ib) x W
M/4 x V x L/2 = (M (L/2)^2 + 1/3xMxL^2) x W
M/8 X VL = (ML^2/16 + ML^2 /3 )
After elimination we have,
V/8 = 19/48 x L x W
W = 48/8 x V/19L = 6/19 x V/L
Therefore W = (0.136)X V/L
Answer:
a) Yes, there are 
shakes in a second (
) in a year there are 31,536,000 seconds... that is 3.1536x
(
)
b) Note that the defined universe day will have 60*60*24=86400 universe seconds if the seconds are defined as normal seconds.
Also one universe day (or 86400 universe seconds) is equivalent to 1010 years. Now using a rule of three we can know the seconds that humans have existed.
That is about 2 and half hours.
Answer:
Explanation:
In multiplications or divisions, the result must be written using a number of significant figures equal to the smallest number of significant figures contained in the original numbers.
For instance, in this case the two numbers are:
3278 --> 4 significant figures
42 --> 2 significant figures
So, the product must be written using 2 significant figures.
Calculating the product, we get:
Therefore, using 2 significant figures only, the result is
