What is the average speed of a car that traveled 300 meters in 5.5 seconds?
1 answer:
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Answer:
The speed of the electron is 1.371 x 10⁶ m/s.
Explanation:
Given;
wavelength of the ultraviolet light beam, λ = 130 nm = 130 x 10⁻⁹ m
the work function of the molybdenum surface, W₀ = 4.2 eV = 6.728 x 10⁻¹⁹ J
The energy of the incident light is given by;
E = hf
where;
h is Planck's constant = 6.626 x 10⁻³⁴ J/s
f = c / λ
Photo electric effect equation is given by;
E = W₀ + K.E
Where;
K.E is the kinetic energy of the emitted electron
K.E = E - W₀
K.E = 15.291 x 10⁻¹⁹ J - 6.728 x 10⁻¹⁹ J
K.E = 8.563 x 10⁻¹⁹ J
Kinetic energy of the emitted electron is given by;
K.E = ¹/₂mv²
where;
m is mass of the electron = 9.11 x 10⁻³¹ kg
v is the speed of the electron
Therefore, the speed of the electron is 1.371 x 10⁶ m/s.
Answer:
C).
Explanation:
As we know that capacitance of a given capacitor is
now we know that energy stored in the capacitor plates
here if all the dimensions of the capacitor plate is doubled
then in that case
here area becomes 4 times on doubling the radius and the distance between the plates also doubles
So new capacitance is now
so capacitance is doubled
now the final energy stored between the plates of capacitor is given as
so the final energy is
Answer:
The speed of the sound wave on the string is 545.78 m/s.
Explanation:
Given;
mass per unit length of the string, μ = 4.7 x 10⁻³ kg/m
tension of the string, T = 1400 N
The speed of the sound wave on the string is given by;
where;
v is the speed of the sound wave on the string
Substitute the given values and solve for speed,v,
Therefore, the speed of the sound wave on the string is 545.78 m/s.