Simon Bridge said:How much work to get the first smallest bit of charge onto the sphere (from infinity)?
How about the next bit?
The bit after that?
... spot the pattern.
Either that or look up the equation for the amount of energy stored in a charged metal sphere.
Simon Bridge said:So how can you tell if it is the right equation?
i.e. read the book carefully: what exactly does it say this is the energy of?
... is that exactly what it says?need_aca_help said:Energy stored by a charged sphere
Simon Bridge said:... is that exactly what it says?
Not just what's written down - there is usually a diagram as well.
i.e. is the sphere uniformly charged? Is the charge distributed through the whole volume or just on the surface? Is the sphere a conductor or an insulator?
If you cannot narrow this down you will have to do some calculus.
The charge on a sphere can be determined using the principle of conservation of energy. This means that the total energy of the system (sphere and its surroundings) remains constant. By measuring the potential energy of the sphere at different distances from a fixed point, the charge can be calculated using the equation Q = k(R1-R2), where Q is the charge, k is the Coulomb constant, and R1 and R2 are the distances at which the potential energy is measured.
The Coulomb constant, denoted by k, is a fundamental constant in electrostatics that relates the force between two point charges to their distance and magnitude. Its value is approximately equal to 8.99 x 10^9 Nm^2/C^2.
Yes, the method can be applied to any type of sphere, regardless of its size or composition. As long as the sphere has a well-defined surface and the charge is uniformly distributed on it, the method will yield an accurate result.
Yes, this method is highly accurate. As long as the potential energy is measured accurately and the Coulomb constant is used correctly, the calculated charge will be very close to the actual value.
The main limitation of this method is that it can only be applied to spheres with a uniform charge distribution. If the charge is not uniformly distributed, the calculated charge may not be accurate. Additionally, this method assumes that the sphere is isolated from other charges, as any external charges can affect the potential energy and thus, the calculated charge.