When vapor pressure equals atmospheric pressure, it's called boiling point of that liquid.
Answer:
The electric field is 
Explanation:
Given that,
Radius = 0.357 m
Charge 
Point charge 
Distance = 0.815 m
We need to calculate the total electric field
Using formula of electric field

Where, q = point charge
r = distance
Put the value into the formula


Hence, The electric field is 
Answer:
Proton, stable subatomic particle that has a positive charge equal in magnitude to a unit of electron charge and a rest mass of 1.67262 × 10−27 kg, which is 1,836 times the mass of an electron.
Check the attached file for the solution for this problem.
To develop this problem it is necessary to apply the concepts related to Wavelength, The relationship between speed, voltage and linear density as well as frequency. By definition the speed as a function of the tension and the linear density is given by

Where,
T = Tension
Linear density
Our data are given by
Tension , T = 70 N
Linear density , 
Amplitude , A = 7 cm = 0.07 m
Period , t = 0.35 s
Replacing our values,



Speed can also be expressed as

Re-arrange to find \lambda

Where,
f = Frequency,
Which is also described in function of the Period as,



Therefore replacing to find 


Therefore the wavelength of the waves created in the string is 3.49m