Answer:
Emechanical=mgh+mν²
Explanation:
The equation for the total mechanical energy is:
Emechanical=Epotential+Ekinetic
In which,
Epotential=mgh; m: mass of the body, g: gravity; h: height
Ekinetic=mν²; m: mass of the body, ν: velocity of the body
So,
Emechanical=mgh+mν²
Answer:
explanation of this effect is the photoelectric effect
Explanation:
Let's describe the process, when light of large wavelength falls, this implies a small energy, according to Planck's equation
E = h f =
the energy of the photons is not enough to carry out an electronic transition between two states of the material, when we decrease the wavelength (the energy of the photons increases), the point is reached where the energy of the beam is equal to some energy of a transition, by which the electrons are promoted and since we can see a certain charge, as the atoms are neutral, some electrons must be removed from the material, this is represented in the macroscopic case as the work function of the material, consequently a unbalanced load that is what we can measure.
When we increase the lightning intensity, what we do is that we increase the number of photons and if each photon can remove an electron, by removing the electrons the difference between it and the positive charge (fixed in the nuclei) increases.
We can analyze the interaction of the photon and the electron as a particular collision.
The explanation of this effect was made by Einstein in his explained of the photoelectric effect
Answer: 3.49 s
Explanation:
We can solve this problem with the following equation of motion:
(1)
Where:
is the final height of the ball
is the initial height of the ball
is the initial velocity (the ball was dropped)
is the acceleratio due gravity
is the time
Isolating :
(2)
(3)
Finally we find the time the ball is in the air:
(4)