# Moving Particle and Different Fields

1. Mar 4, 2007

### Soaring Crane

1. The problem statement, all variables and given/known data

The region of space around a moving proton contains

a. a gravitational field only.

b. a magnetic field only.

c. an electric field only.

d. an electric, magnetic and gravitational field.

e. an electric and magnetic field only.

2. Relevant equations

(conceptual question) See below.

3. The attempt at a solution

I know that both a magnetic field and an electric field apply to a dynamic particle, but I am unsure of the gravitational field. Does a gravitational field only apply to stationary particles?

Thanks.

2. Mar 4, 2007

### robb_

The earth is not a particle but it moves, depending on frame. Does it exert/experience a gravitational field?

3. Mar 4, 2007

### Soaring Crane

Yes, it does.

4. Mar 4, 2007

### robb_

Does a proton have mass?

5. Mar 4, 2007

### Soaring Crane

Yes. Will it also experience a gravitational field?

6. Mar 4, 2007

### robb_

You asked if only a stationary mass experiences a g field.
I gave you an example of a moving mass that experiences a g field.

7. Mar 4, 2007

### Soaring Crane

Therefore, from the example with the earth, the moving proton will feel a gravitational field's effects?

8. Mar 4, 2007

### robb_

Yes. remember that the g force is "weak" relative to the other fundamental forces though.