Answer:
LAW 1 : For a given metal and frequency, the number of photoelectrons emitted is directly proportional to the intensity of the incident radiation.
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LAW 2: For a given metal, there exists a certain frequency below which the photoelectric emission does not take place. This frequency is called threshold frequency.
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LAW 3: For a frequency greater than the threshold frequency, the kinetic energy of photoelectrons is dependent upon frequency or wavelength but not on the intensity of light.
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LAW 4: Photoelectric emission is an instantaneous process. The time lag between incidence of radiations and emission of electron is 10^-9 seconds.
Explanation:
Answer:
10.8 s
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 0 m/s
Acceleration (a) = 5 m/s/s
Distance travelled (s) = 291 m
Time (t) taken =?
We can calculate the time taken for the car to cover the distance as follow:
s = ut + ½at²
291 = 0 × t + ½ × 5 × t²
291 = 0 + 2.5 × t²
291 = 2.5 × t²
Divide both side by 2.5
t² = 291 / 2.5
t² = 116.4
Take the square root of both side
t = √116.4
t = 10.8 s
Thus, it will take the car 10.8 s to cover the distance.
Answer:
Explanation:
m₂ is hanging vertically and m₁ is placed on inclined plane . Both are in limiting equilibrium so on m₁ , limiting friction will act in upward direction as it will tend to slip in downward direct . Tension in cord connecting the masses be T .
For equilibrium of m₁
m₁ g sinα= T + f where f is force of friction
m₁ g sinα= T + μsx m₁ g cosα
m₁ g sinα - μs x m₁ g cosα = T
For equilibrium of m₂
T = m₂g
Putting this value in equation above
m₁ g sinα - μs x m₁ g cosα = m₂g
m₂ = m₁ sinα - μs x m₁ cosα
Answer:
The correct answer is c
Explanation:
When a body is in rotational equilibrium, the relationship must be met
∑ τ = 0
Σ F d = 0
therefore the forces that are exerted on the body that are represented in the center of gravity are different from zero, therefore, to maintain balance the distance must be zero, therefore the center of gravity must be above the leg where the body is balancing
The correct answer is c
