Answer:
They encircle the planet
times.
Step-by-step explanation:
Consider the provided information.
We have 2.5 mole of dust particles and the Avogadro's number is 
Thus, the number of dust particles is:

Diameter of a dust particles is 10μm and the circumference of earth is 40,076 km.
Convert the measurement in meters.
Diameter: 
If we line up the particles the distance they could cover is:

Circumference in meters:

Therefore,

Hence, they encircle the planet
times.
Answer:
0,55
Step-by-step explanation:
Answer:
and 
Step-by-step explanation:
Given:
Equation 1:

Simplifying the above equation by dividing both sides by 100


Equation 2:

Simplifying the above equation by dividing both sides by 400.


Now the system of equation is:
(1a) 
(2a) 
Solving by elimination
Multiplying equation (2a) with 

(2b) 
Adding equations (1a) and (2b) in order to eliminate 

+ 
We get 
∴ 
Plugging
in equation (2a).

Adding
both sides.

∴ 
Answer:

Step-by-step explanation:
The distance formula tells you the distance d between the points (0, 0, 0) and (-3, -b, c) is ...
d = √((x2 -x1)² +(y2 -y1)² +(z2 -z1)²) = √((-3-0)² +(-b-0)² +(c-0)²)
= √(9 +b² +c²)