What is the force between two small charged spheres having charges of #2 times 10^7# C and #3 times 10^7# C placed 30 cm apart in air?
1 Answer
Explanation:
We're asked to find the magnitude of the electric force between two point charges.
To do this, we can use the equation
#F_"e" = k(q_1q_2)/(r^2)#
where

#F_"e"# is the magnitude of the electric force (in newtons) 
#k# is Coulomb's constant, equal to#8.988xx10^9("N"·"m"^2)/("C"^2)# 
#q_1# and#q_2# are the point charges (in coulombs), in no particular order 
#r# is the distance between the charges (in meters)
We have:

#k = 8.988xx10^9("N"·"m"^2)/("C"^2)# 
#q_1 = 2xx10^7# #"C"# 
#q_2 = 3xx10^7# #"C"# 
#r = 30# #"cm"# #= ul(0.30color(white)(l)"m"#
Plugging in known values:
#F_"e" = (8.988xx10^9("N"·cancel("m"^2))/(cancel("C"^2)))((2xx10^7cancel("C"))(3xx10^7cancel("C")))/((0.30cancel("m"))^2)#