How much energy is stored by the electric field between two square plates, 8.1 cm on a side, separated by a 1.9-mm air gap? The charges on the plates are equal and opposite and of magnitude 17 nC . Express your answer using two significant figures and include the appropriate units.

4.66×10^-6J

Explanation:

The capacitance of a capacitor is given by:

C= ε A/d

ε= permittivity of free space

A= Area of the plates

d= distance between the plates.

A= (8.1×10-2)^2= 65.61×10^-4m2

d= 1.9× 10^-3m

ε= 8.85×10^-12

C= 8.85×10^-12 × 65.61×10^-4/1.9× 10^-3

C= 3.1×10^-11 F

Energy stored in a capacitor= q^2/2C

But q= 17×10-9

E= (17×10^-9)^2/2×3.1×10^-11

E= 4.66×10^-6J

if the forces acting on an object are unbalanced, the object will accelerate in the direction of the net force on the object.

explanation:

this is best explained by having an understanding of newton's second law, which states that f=ma. you see, when the forces are unbalanced, net force (sum of all forces) is not zero. therefore making it necessary for the object to have an acceleration in the direction of the net force.