Answer:
a) variation of the energy is equal to the work of the friction force
b) W = Em_{f} -Em₀
, c) he conservation of mechanical energy
Explanation:
a) In an analysis of this problem we can use the energy law, where at the moment the mechanical energy is started it is totally potential, and at the lowest point it is totally kinetic, we can suppose two possibilities, that the friction is zero and therefore by equalizing the energy we set the velocity at the lowest point.
Another case is if the friction is different from zero and in this case the variation of the energy is equal to the work of the friction force, in value it will be lower than in the calculations.
b) the calluses that he would use are to hinder the worker's friction force and energy
W = Em_{f} -Em₀
N d = ½ m v² - m g (y₂-y₁)
y₂-y₁ = 35 -10 = 25m
c) if there is no friction, the physical principle is the conservation of mechanical energy
If there is friction, the principle is that the non-conservative work is equal to the variation of the energy
Answer:
It's energy will double.
Explanation:
This is because energy, E, is related to frequency, f, by:
E = hf
Where h = Planck's constant
So, double frequency will be 2f
=> E(2f) = 2hf = 2E.
Hence, energy is doubled.
Answer:
1178 nm
Explanation:
We are given that
Wavelength of light=
We have to find the thickness of spacer if five dark fringes are observed between the edges of the glass.
Suppose that first dark fringe and fifth dark fringe near spacer, then the path length of light is 4 times the wavelength of light.
The light passes through air film is two times then the change in air film thickness from one edge to other is two times the wavelength of light.
Change in air film thickness from one edge to other edge is same as the thickness of spacer.
Therefore, thickness of spacer=
Thickness of spacer=
m
Thickness of spacer=1178 nm
Hence, the thickness of spacer=1178 nm
