#importing modules
import math
from __future__ import division
#Variable declaration
r=0.053*10**-9; #distance(m)
q1=1.6*10**-19; #charge on electron(C)
q2=1.6*10**-19; #charge on proton(C)
#let x=1/(4*math.pi*epsilon0)
x=9*10**9;
#Calculation
F=x*q1*q2/(r**2); #force of attraction(N)
#Result
print "force of attraction is",round(F*10**8,1),"*10**-8 N"
#importing modules
import math
from __future__ import division
#Variable declaration
r=2; #distance(m)
q1plusq2=5*10**-4; #positive charge(C)
#let x=1/(4*math.pi*epsilon0)
x=9*10**9;
F=1; #force(N)
#Calculation
q1q2=F*(r**2)/x; #product of charges(C**2)
q1minusq2=math.sqrt((q1plusq2**2)-(4*q1q2)); ##difference of charges(C)
twoq1=q1plusq2+q1minusq2;
q1=twoq1/2; #charge on individual sphere(C)
twoq2=q1plusq2-q1minusq2;
q2=twoq2/2; #charge on individual sphere(C)
#Result
print "the charges on individual spheres are",round(q1*10**4,3),"*10**-4 and",round(q2*10**4,3),"*10**-4"
#importing modules
import math
from __future__ import division
#Variable declaration
m=9.1*10**-31; #mass of electron(kg)
g=9.8; #acceleration due to gravity(m/sec**2)
q=1.6*10**-19; #charge on electron(C)
#Calculation
F1=m*g; #force by electron(N)
E=F1/(2*q); #intensity of electric field(N/C)
#Result
print "intensity of electric field is",round(E*10**11,3),"*10**-11 N/C"
#importing modules
import math
from __future__ import division
#Variable declaration
r=12*10**-2; #distance(m)
q1=2*10**-7; #charge(C)
q2=8.5*10**-8; #charge(C)
#let x=1/(4*math.pi*epsilon0)
x=9*10**9;
#Calculation
E1=x*q2/(r**2); #intensity at electric field at q1 due to q2(N/C)
E2=x*q1/(r**2); #intensity at electric field at q2 due to q1(N/C)
F=x*q1*q2/(r**2); #force of attraction(N)
#Result
print "intensity at electric field at q1 due to q2 is",round(E1*10**-5,2),"*10**5 N/C"
print "intensity at electric field at q1 due to q2 is",round(E2*10**-5,2),"*10**5 N/C"
print "force of attraction is",round(F,4),"N"