Answer:
a) True. The number of photoelectrons is proportional to the amount (intensity) of the incident beam. From the expression above we see that threshold frequency cannot emit electrons.
b) λ = c / f
Therefore, as the wavelength increases, the frequency decreases and therefore the energy of the photoelectrons emitted,
c) threshold energy
h f =Ф
Explanation:
It's photoelectric effect was fully explained by Einstein by the expression
Knox = h f - fi
Where K is the kinetic energy of the photoelectrons, f the frequency of the incident radiation and fi the work function of the metal
a) True. The number of photoelectrons is proportional to the amount (intensity) of the incident beam. From the expression above we see that threshold frequency cannot emit electrons.
b) wavelength is related to frequency
λ = c / f
Therefore, as the wavelength increases, the frequency decreases and therefore the energy of the photoelectrons emitted, so there is a wavelength from which electrons cannot be removed from the metal.
c) As the work increases, more frequency radiation is needed to remove the electrons, because there is a threshold energy
h f =Ф
To solve this problem it is necessary to consider two concepts. The first of these is the flow rate that can be defined as the volumetric quantity that a channel travels in a given time. The flow rate can also be calculated from the Area and speed, that is,
Q = V*A
Where,
A= Cross-sectional Area
V = Velocity
The second concept related to the calculation of this problem is continuity, which is defined as the proportion that exists between the input channel and the output channel. It is understood as well as the geometric section of entry and exit, defined as,


Our values are given as,


Re-arrange the equation to find the first ratio of rates we have:



The second ratio of rates is



Answer:
1.9 MPa
Explanation:
Mass of person = 81 kg
Mass of chair = 3.8 kg
Diameter of contact point = 1.2 cm = D
Radius of contact point = 1.2/2 = 0.6 cm
Total mass of chair and person = 81 + 3.8 = 84.8 kg = M
Acceleration due to gravity = 9.81 m/s²
Force acting on the floor
<em>F = Mg</em>
<em>⇒F = 84.8×9.81</em>
<em>⇒F = 831.888 N</em>
Area of the contact point
<em>A = πR²</em>
<em>⇒A = π0.006²</em>
<em>⇒A = π0.000036 m²</em>
Area of the four points is
<em>4A = 0.000144π m²</em>
Pressure

Pressure exerted on the floor by each leg of the chair is 1.9 MPa