Question

There is an infinitely large positively charged metal plate. On the right of the plate, two point-charges Q1 = -6.7 μC and Q2 = 1.8 μC are placed. The line connecting Q1 and Q2 is perpendicular to the charged plate. The distance between the plate and Q1 is D = 0.20 m, and the distance between Q1 and Q2 is d = 0.34 m. If the charge density in the plate σ is 1.3 μC/m2 , find the electric force on Q1 in N. If the force's direction is in the right (left) direction, it is positive (negative) (20 points).

Answer 1

Ans

The electric force on Q1 will be due to the plate and particle Q2

So the net electric force on Q1 will be like this == (kq₁q₂/ r² +  σq₁/ε )

= ((9 × 10⁹ Nm²/ C² *6..7*1.8*10^-12)/0.115) + (1.3 μC/m²* 6.7*10^-6/ 8.854 × 10^-12 C² N^-1 m^-2 )

= 943.82 + 0.98

= 944.80 N