Answer:
Part a)

Part b)

Explanation:
As we know that electric force on electric charge is given as

here we have

E = 153 N/C
now force is given as

Gravitational force on electric charge near surface of earth is given as


now the ratio of two forces is given as


Part b)
Now the ball is balanced by the electric force and the force of gravity on it
so here we have



here we have

Answer:
this is a no brainer
Explanation:
As air pressure in an area increases, the density of the gas particles in that area increases.
Explanation:
1)
A) Bb BB
B) 50%
2)
A) 50%
B) <u> </u><u> </u><u> </u><u> </u><u> </u><u>b</u><u>.</u><u> </u><u> </u><u> </u><u>b</u>
B. Bb. Bb
b. bb. bb
Answer:
The duration is ![T =72 \ years /tex]Explanation:From the question we are told that The distance is [tex]D = 35 \ light-years = 35 * 9.46 *10^{15} = 3.311 *10^{17} \ m](https://tex.z-dn.net/?f=T%20%20%3D72%20%5C%20%20years%20%2Ftex%5D%3C%2Fp%3E%3Cp%3EExplanation%3A%3C%2Fp%3E%3Cp%3EFrom%20the%20question%20we%20are%20told%20that%20%3C%2Fp%3E%3Cp%3E%20%20%20%20The%20%20distance%20is%20%20%5Btex%5DD%20%20%3D%20%2035%20%5C%20light-years%20%3D%2035%20%2A%20%209.46%20%2A10%5E%7B15%7D%20%3D%203.311%20%2A10%5E%7B17%7D%20%5C%20%20m%20)
Generally the time it would take for the message to get the the other civilization is mathematically represented as

Here c is the speed of light with the value 
=> 
=> 
converting to years



Now the total time taken is mathematically represented as

=> 
=> [tex]T =72 \ years /tex]
Cm^3 is same as mL
13.5 g / 5 mL = 2.7 g/mL
look up densities of metals
aluminum has a density of 2.7 g/mL