Answer:
The new force on the test charge is 145.02N
Explanation:
Force on a unit positive charge can be calculated using coulomb's law.
F =Kq²/r²
Where
F is the force on the charge = 321 N
K is a constant = 8.99 X10⁹ Nm²/C²
q is a test charge = 4.89 μC = 4.89 X10⁻⁶ C
r is the distance between the charge and the surface = 4.1cm
F ∝1/r²
Force on the charge is inversely proportional the square of distance between the charge and the surface.
Fr² = constant
F₁r₁² = F₂r₂²
F₂ = F₁r₁²/r₂²
If the charge is then moved 2.00 cm farther away from the surface;
The new distance becomes 4.10 cm + 2.00 cm = 6.1 cm
Therefore, r₂ = 6.1 cm, r₁ = 4.1 cm, F₁ =321 N
F₂ = (321 X4.1²)/(6.1²)
F₂ = 145.02N
Therefore, The new force on the test charge is 145.02N
