# Suppose a spaceship changes velocity relative to Earth, so that the duration of the laser pulses…

Question:

🖥**If the atom is the basic unit of life, does that make Biology a branch of Physics?**

ANSWER:

Atoms:

Atoms are the smallest building units of the entire universe and their properties define the state of matter, as well its characteristics. Atoms have an internal structure and contain an even smaller region that is called the nucleus.

*Answer and Explanation:*

The theory that describes, with an excellent degree of accuracy, the properties, internal structure, and the total dynamic behavior of the atoms is the quantum theory. Quantum theory counts more than 120 years of existence and one can argue that it is the theory that radically changed the physical world.

On the other hand, biology is not a fundamental science and uses various principles from physics and chemistry in order to interpret the patterns of big molecules. Moreover, if we consider that the atom is actually the unit of life, we can definitely argue that Biology is a branch of Physics since the behavior of atoms is ruled by quantum mechanics.

🖥**Give a one-word term for: 1. changing momentum. 2. unimpeded motion of an object, falling under…**

👉Question:

**Give a one-word term for:**

>>changing momentum.

>>unimpeded motion of an object, falling under the influence of only gravity.

>>the phenomen that waves bend around the edges of an obstacle.

>>the force per unit charge, at a point in an electric field.

>>the vector sum of the force acting on an object.

**Answer and Explanation:**

✍force

✍free fall

✍diffraction

✍electric field strength

✍net force

🖥Question:

**What is theoretical astrophysics?**

*✍Astrophysics:*

Astrophysics is a very important part of astronomy that deals with the underlying physics and mechanisms that take place within astronomical objects, such as planets, stars, and even galaxies. All these objects emit some kind of electromagnetic radiation that can be collected through suitable equipment and analyzed in terms of relative intensity, wavelength and a possible shift in light trajectory due to the existence of dark matter.

*👉Answer and Explanation:*

Theoretical astrophysics employs the laws of quantum physics and chemistry in order to understand the internal structure of various objects in the universe. It employs a variety of theoretical tools, such as analytical and numerical models in order to compromise the results obtained from the experimental data and the theoretical predictions.

Several interesting topics are examined in theoretical astrophysics including galaxy formation and spinning effect, star creation and collapse, the impact of general relativity theory in the universe as well as the practical implication of string theory (i.e. black holes, event horizon). The Bing Bang conjecture is a famous theory that has been created from theoretical astrophysicists.

*Question:*

**Why are general relativity and quantum mechanics incompatible?**

*General Relativity and Quantum Mechanics:*

The General Theory of Relativity (GR) is the prevailing theory of gravity, applicable at the heaviest and largest scales, which, in a nutshell, states that gravity is a manifestation of space time being warped by the presence of matter and energy. Quantum mechanics (QM) on the other hand, deals with the small, such as elementary particles, and is the theory of the other fundamental forces of nature: the strong nuclear force, the weak nuclear force, and the electromagnetic force. In it, the energy states of particles are said to be discrete and quantized.

*👉***Answer and Explanation:**

Both theories work very well in their respective domains of influence. However, certain regions in the universe, such as the center of a black hole or the very early universe (at the Big Bang), suggest properties that are both heavy (where general relativity is useful) and small (where quantum mechanics is useful). Both theories have to be unified; however, it is very difficult to unify these theories because>>

(1) Their underlying philosophies are different; whereas general relativity is deterministic, quantum mechanics is probabilistic, and hence each theory uses different mathematics.

(2) General relativity describes space time as smooth and malleable, while quantum mechanics suggests that the constituents of matter be discrete; a theory of quantized gravity first has to be realized before the unification. Theories such as string theory and loop quantum gravity are making strides in this unification, however, none of these has produced verifiable predictions yet, and this remains a challenge in modern physics.

## Question:

Suppose a spaceship changes velocity relative to Earth, so that the duration of the laser pulses as seen on Earth is 7.40×10−6*s* What is the spaceship’s velocity (m/s) relative to Earth.

## Relative Velocity:

Whenever the velocities of two bodies are compared, the concept of relative velocity is taken into consideration. This velocity is found with respect to a reference medium.

## Answer and Explanation:

Using the relation for relative velocity of the spaceship:

*v*=*c*√(1−(Δ*t**o*Δ*t*)2)

Substituting the values in the equation, we will get the velocity of the spaceship:

*v*=3×108√(1−(2.20×10−67.40×10−6)2)