Answer:
Please see below as the answer is self- explanatory.
Explanation:
- Any time that an object changes direction (from leftward to rightwward, or from upward to downward) the velocity must be zero just for one instant, when is on the verge of changing the direction.
- This is needed because velocity changes as a continuous function of time, so it needs to cross the t-axis when passing from positive to negative or vice versa.
- However, the claim that in the moment that velocity is zero, the acceleration is also zero, is false.
- Due to acceleration is the rate of change of velocity, and velocity is a vector, this means at any time there is a change of direction, there is an acceleration that is non-zero.
- For example, when an object that has been thrown upward, reaches to its maximum height, just one instant before starting to fall, the velocity becomes zero, but the acceleration (which causes the object to fall) is non-zero, due to it's the acceleration due to gravity.
Answer:
Honestamente yo no se cual es la pregunta que escribiste
Answer:

Explanation:
Rydberg's formula is used to describe the wavelengths of the spectral lines of chemical elements similar to hydrogen, that is, with only one electron being affected by the effective nuclear charge. In this formula we can find the rydberg constant, knowing the wavelength emitted in the transcision between two energy states, we can have a value of the constant.

Where
it is the wavelength of the light emitted, R is the Rydberg constant, Z is the atomic number of the element and
are the states where
.
In this case we have Z=1 for hydrogen, solving for R:

This value is quite close to the theoretical value of the constant 
The force of attraction will decrease when objects move apart