Answer:
The value is 
Explanation:
From the question we are told that
The Coulomb constant is 
The charge on the electron/proton is 
The mass of proton 
The mass of electron is 
Generally for the electron to be held up by the force gravity
Then
Electric force on the electron = The gravitational Force
i.e




I believe this ratio is 4:1 due to the inverse square law
Answer:
1.6 s
Explanation:
To find the time in which the potential difference of the inductor reaches 24V you use the following formula:

V_o: initial voltage = 60V
R: resistance = 24-Ω
L: inductance = 42H
V_L: final voltage = 24 V
You first use properties of the logarithms to get time t, next, replace the values of the parameter:

hence, after 1.6s the inductor will have a potential difference of 24V