# Physics help involving electric field charge

• aaronmilk3
In summary, the conversation discusses finding the charge on a charged sphere based on the speed and location of a proton orbiting at its surface. The formula for electric force and electric field are mentioned as well as the relationship between electric force and centripetal force.

#### aaronmilk3

A proton orbits just at the surface of a charged sphere of radius 0.83 cm. If the speed of the proton is 4.96 X105 m/s, what is the charge on the sphere?

proton mass = 1.67e-27
proton charge = 1.6e-19

I thought maybe F = (mv²)/r
((1.67e-27)(4.96e5)²)/.0083

Then E=F/q

But this doesn't seem to be right.

Any help would be appreciated. I have tried it a couple times with no luck. Just need to get in the right direction. Thank you in advance!

What do you mean on E=F/q? What are E and q?

ehild

E = electric field
q = the charge
F = electric force

You need the charge of the sphere. If E is the electric field strength at the place of the proton, the electric force on the proton is F=eE where e is the elementary charge. How are the electric force and the centripetal force related? How do you get the electric field of the sphere?

ehild

Thanks. I figured it out.

## 1. What is an electric field?

An electric field is a physical field that surrounds an electrically charged particle or object. It is the force that is exerted on other charged particles in the vicinity.

## 2. How is an electric field calculated?

An electric field is calculated by dividing the force acting on a charged particle by the magnitude of the charge of the particle. This is represented by the equation E = F/q, where E is the electric field, F is the force, and q is the charge.

## 3. What factors affect the strength of an electric field?

The strength of an electric field is affected by the distance between the charged particles, the magnitude of the charges, and the medium in which the particles are located. The electric field is stronger when the charges are closer together and weaker when they are further apart.

## 4. How does an electric field interact with electrically charged objects?

An electric field exerts a force on other charged objects in its vicinity. If the objects have opposite charges, they will be attracted to each other, whereas if they have the same charge, they will repel each other.

## 5. What is the relationship between electric field and electric potential?

Electric potential is the potential energy per unit charge of a particle in an electric field. The relationship between electric field and electric potential is given by the equation E = -∇V, where E is the electric field, V is the electric potential, and ∇ is the gradient operator.