Qs.pdf

Coulomb's law states that the magnitude of the electrostatic force between two point charges is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between them.

The graph shows that the electric potential V varies inversely with distance r, indicating that V is proportional to 1/r. All values of V on the graph are negative because the charge Q is negative, resulting in a negative electric potential.

From the graph, the magnitude of Q can be estimated to be about 30 nC.

When a +60 nC charge is moved from r = 0.20 m to r = 0.50 m, the work done can be calculated using the change in electric potential energy.

The electric field strength at r = 0.40 m can be calculated using the electric potential and distance.

For the α particle, its speed is least at point P, where it is closest to the nucleus, due to the conversion of kinetic energy to potential energy.

For the two particles with charges +Q and -2Q, when each is given an additional charge +Q, the resulting charges are +2Q and -Q, resulting in a repulsive force of 1/4 F.

When the distance between two point charges is increased to 20 mm, the force they exert on each other is 0.5 F, indicating that the original distance d is 14 mm, since the force is inversely proportional to the square of the distance.

If the distance between two identical positive point charges is decreased so that the electrical potential energy of Q is doubled, the force of repulsion increases to 4F, since the potential energy is proportional to 1/r and the force is proportional to the gradient of the potential energy.

Coulomb's law states that the magnitude of the electrostatic force between two point charges is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between them.

The electric field surrounding two point charges of +4.0 nC and +6.0 nC can be sketched, with field lines radiating outward from the positive charges.

The magnitude of the electrostatic force acting on the +4.0 nC charge can be calculated using Coulomb's law, given the charges and distance between them.