Answer: C. Expanding
Explanation:
When an object moves away from an observer, the light waves emitted by the object are stretched out making them have move towards the red end of the electromagnetic spectrum, where light has a longer wavelength. This phenomenon is known as the redshift (cosmological redshift). For most astronomical objects, the observed spectral lines are all shifted to longer wavelengths. It is caused solely by the expansion of the Universe and thus, the value of a redshift indicates the recession velocity of the expanding object, or its distance.
Redshift is opposed to the blueshift. Blue light wavelengths tend to be closer together hence blueshift light tends to be emitted from objects that are collapsing.
Without the choices this is difficult to answer but some examples of potential energy are:
- <span>Potential Energy is any type of stored energy. It can be chemical, nuclear, gravitational, or mechanical.
- Stretching a rubber band and holding it. It has potential energy.
- Chemical energy in a battery has potential energy.
Hope this helps!</span>
Atoms<span> are made of three types of sub-atomic particle: neutrons and protons in the nucleus and electrons orbiting the nucleus. </span>Some<span> materials are </span>radioactive<span> because the nucleus of each </span>atom<span> is unstable and gives out nuclear radiation in the form of alpha particles, beta particles or gamma rays.</span>
The force the box is exerting on Manuel is the weight of the box, downward:

and this force is perfectly balanced by the constraint reaction applied by Manuel's hand, pushing upward.