Two charges of # -2 C # and # 3 C# are positioned on a line at points # 3 # and # 4 #, respectively. What is the net force on a charge of # -9 C# at # 0 #?

1 Answer
Jul 22, 2017

Answer:

#2.81*10^9N#

Explanation:

Coulomb's law: #F=(k_eQ_1Q_2)/r^2#, where:
#F# = the force (#N#)
#k_e# = the coulomb constant(#~~8.99*10^9N# #m^2# #C^(-2)#)
#Q_1 &Q_2# = the charge of each particle (#C#)
#r# = the distance (#m#)

Assuming #1# #"unit" = 1m#

Also, assuming a positive resultant force = repulsion, and a negative resultant force = attraction.

For #-9C# and #-2C#:
#F=((8.99*10^9)(-9)(-2))/(3^2)=1.798*10^(10)N#

For #-9C# and #3C#:
#F=((8.99*10^9)(-9)(3))/(4^2)==-1.5170625*10^(10)N#

Net force = #(1.798*10^(10))-(1.5170625*10^(10))=2.809375*10^(9)~~2.81*10^9N#