Answer:
Part a)
Part b)
Direction = upwards
Explanation:
When ball is dropped from height h = 4.0 m
then the speed of the ball just before it will strike the ground is given as
Now ball will rebound to height h = 2.00 m
so the velocity of ball just after it will rebound is given as
Part a)
Average acceleration is given as
Part B)
As we know that ball rebounds upwards after collision while before collision it is moving downwards
So the direction of the acceleration is vertically upwards
Answer:
As you may know, each element has a "fixed" number of protons and electrons.
These electrons live in elliptical orbits around the nucleus, called valence levels or energy levels.
We know that as further away are the orbits from the nucleus, the more energy has the electrons in it. (And those energies are fixed)
Now, when an electron jumps from a level to another, there is also a jump in energy, and that jump depends only on the levels, then the jump in energy is fixed.
Particularly, when an electron jumps from a more energetic level to a less energetic one, that change in energy must be compensated in some way, and that way is by radiating a photon whose energy is exactly the same as the energy of the jump.
And the energy of a photon is related to the wavelength of the photon, then we can conclude that for a given element, the possible jumps of energy levels are known, meaning that the possible "jumps in energy" are known, which means that the wavelengths of the radiated photons also are known. Then by looking at the colors of the bands (whose depend on the wavelength of the radiated photons) we can know almost exactly what elements are radiating them.
The correct answer is rock cycle
The answer is true. All the galaxies in the universe follow
the law of gravity.
<span>Based from the book, It's about Time: the Illusion of
Einstein’s Time Dilation Explained, </span>
Einstein had explained that all the heavenly bodies in the
universe follow the same scientific laws that are similar to our solar system. The
stars and planets are held by the principles of inertia and gravity
Not if both speeds are in the same units.
However, if the 254 is 'centimeters per time' and the 100 is 'inches per time',
then the speeds are equal.
