Which are properties of liquid crystals

Keaton is asked to solve the following physics problem:

RideAnS [48]

Answer:

The answer is C "think about the problem first, systematically consider all factors, and form a hypothesis"

Explanation:

In physics there is some basic fomula that sir Isacc Newton proposed under the topic of motion. The three formulas are below;

1) v=u+at

2)v^2=u^2+2as

3)s=ut+(1/2)(at^2)

the variables are explained below;

u= initial velocity of the body

a=acceleration/Speed of the body

t= time taken by the body while travelling

s= displacement of the body.

Therefore to solve keatons problem, the factors(variables) in the formulas above need to be systematically considered. Since the ball was dropped from the top of the building, the initial velocity is 0 because the body was at rest. Also the acceleration will be acceleration due to gravity (9.8m/s^2)

5 0

4 years ago

Using Newton's Second Law, can you explain why one of the major advancements in spaceflight was the development of strong cerami

katovenus [111]

Answer:

high density can withstand high acceleration and applied forces

Heavy metals are toxic to humans,

the clay is quite abundant and in general it is not toxic

Explanation:

The selection of materials for the construction of rockets takes into account many aspects, the technical resistance to the demands of space travel, but also the abundance of the material. Heavy metals have two very serious problems. The first one, some of them are a little scarce in nature, but the most serious problem is that almost all of them are toxic to humans, for example: lead and mercury.

On the other hand, the clay is quite abundant and in general it is not toxic to living beings.

If we use Newton's second law

F = m a

let's use the concept of density

rho = m / V

m = rho V

let's substitute

F = rho V a

From this expression we see that a material with high density can withstand high acceleration and applied forces, such as those existing in spacecraft clearance and re-entry to Earth.

Unfortunately with this law there is no criterion to select a material unless its density is high, in addition to this criterion low toxicity criteria for human beings are used,

8 0

3 years ago

Practice entering numbers that include a power of 10 by entering the diameter of a hydrogen atom in its ground state, dH = 1.06

Slav-nsk [51]

Answer:

$1.06085\times 10^{-10}\ m$

Explanation:

h = Planck's constant = $6.626\times 10^{-34}\ m^2kg/s$

m = Mass of electron = $9.11\times 10^{-31}\ kg$

k = Coulomb constant = $8.99\times 10^{9}\ Nm^2/C^2$

e = Charge of electron = $1.6\times 10^{-19}\ C$

n = 1 (ground state)

Angular momentum is given by

$L=mvr$

From Bohr's atomic model we have

$L=\dfrac{nh}{2\pi}$

$mvr=\dfrac{nh}{2\pi}\\\Rightarrow v=\dfrac{nh}{2\pi mr}$

The centripetal force will balance the electrostatic force

$\dfrac{ke^2}{r^2}=\dfrac{mv^2}{r}\\\Rightarrow \dfrac{ke^2}{r}=mv^2\\\Rightarrow \dfrac{ke^2}{r}=m(\dfrac{nh}{2\pi mr})^2\\\Rightarrow r=\dfrac{n^2h^2}{4\pi^2mke^2}\\\Rightarrow r=\dfrac{1^2\times (6.626\times 10^{-34})^2}{4\pi^2 \times 9.11\times 10^{-31}\times 8.99\times 10^{9}\times (1.6\times 10^{-19})^2}\\\Rightarrow r=5.30426\times 10^{-11}\ m$