10.1 Describing Fields

per unit mass on a mass placed at P

on a mass placed at P

per unit mass on a small point mass placed at P

on a small point mass placed at P

for both electric and gravitational fields

for electric fields only

for gravitational fields only

for neither electric or gravitational fields

0

It is analogous to the electric potential at a point in an electric field

It is a vector quantity

It is defined as negative because work must be done on a mass to move it to infinity

It is inversely proportional to the distance between masses

The equipotential lines are straight

The equipotential lines are evenly spaced

The equipotential lines become progressively further apart

The equipotential lines are perpendicular to the field lines

When the small charge is moved from Q to P or R to S the work done is the same in each case

The small charge has a larger potential energy at Q than at S

When the small charge is moved from Q to R it is twice the work done in moving it from P to S

The small charge has a larger electric potential energy at R than at S

The field lines around a point mass and negative point charge are identical

The work done in each field is either the product of the mass and change in potential or charge and change in potential

The gravitational potential and electric potential both have a relationship

The gravitational and electrostatic forces are always attractive

J

V

N kg^–1

J kg^–1