A judgement or an observation?
Before the fall, at 1.50 m, all the energy is potential and none is kinetic.
As it's falling the apple has both kinetic and potential energies. The decrease in potential energy is equal to the increase in kinetic energy
KE = -ΔPE
= -mgΔh
= -(0.100 kg)(9.81 m/s²)(1.00 m - 1.50 m)
= 0.491 J
The question is incomplete. The complete question is :
A plate of uniform areal density 
is bounded by the four curves:
where x and y are in meters. Point 
has coordinates 
and 
. What is the moment of inertia 
of the plate about the point ?
Solution :
Given :
and , 
, 
.
So,
, 
![$I=2 \int_1^2 \left( \left[ (x-1)^2y+\frac{(y+2)^3}{3}\right]_{-x^2+4x-5}^{x^2+4x+6}\right) \ dx$](https://tex.z-dn.net/?f=%24I%3D2%20%5Cint_1%5E2%20%5Cleft%28%20%5Cleft%5B%20%28x-1%29%5E2y%2B%5Cfrac%7B%28y%2B2%29%5E3%7D%7B3%7D%5Cright%5D_%7B-x%5E2%2B4x-5%7D%5E%7Bx%5E2%2B4x%2B6%7D%5Cright%29%20%5C%20dx%24)
So the moment of inertia is 
.
The gravitational force experienced by Earth due to the Moon is <u>equal to </u>the gravitational force experienced by the Moon due to Earth.
<u>Explanation</u>:
The force that attracts any two objects/bodies with mass towards each other is defined as gravitational force. Generally the gravitational force is attractive, as it always pulls the masses together and never pushes them apart.
The gravitational force can be calculated effectively using the following formula: F=GMmr^2
where “G” is the gravitational constant.
Though gravity has the ability to pull the masses together, it is the weakest force in the nature.
The mass of the Earth and moon varies, but still the gravitational force felt by the Earth and Moon are alike.
Answer:
The electronic transition of an electron back to a lower energy level generates an emission spectrum.
Explanation:
The atomic emission spectrum¹ of an element has its origin when an electronic transition² occurs. An electron in an atom or ion³will absorb energy coming from a source and pass to a higher energy level, the electron, upon returning to its base state will emit a photon⁴ or a series of photons.
Hence, that leads to the formation of an emission spectrum.
Remember that an electron has energy levels in an atom or ion, at which each energy level has a specific value.
The energy values will differ from one element to another. So, it can be concluded that each element has a unique pattern of emission lines.
Key terms:
¹Spectrum: Decomposition of light in its characteristic colors.
²Electronic transition: When an electron passes from one energy level to another, either for the emission or absorption of a photon.
³Ion: An atom electrically charged due to the gain or loss of electrons.
⁴Photon: Elementary particle that constitutes light.
