11A.2 Gravitational Fields

Question 1

any gravitational field formed by a mass in space will

Answer 1

be radial in shape, and will always point towards the small since gravity is always attractive

Question 2

in outer space, where it is the furthest possible from galaxy or any other particles, there are regions where

Answer 2

there is almost no gravity

Question 3

what is the gravitational field strength formula

Answer 3

g = GM/r^2 which states that the grav field strength is independent of the mass of the object being acted on

Question 4

how do we derive g=GM/r^2

Answer 4

page 172

Question 5

what can the gravitational field strength formula prove

Answer 5

that their are some regions in outer space that have almost no gravity acting on them

Question 6

what is gravitational potential

Answer 6

the amount of work done per unit mass to move an object form an infinite distance to that point in the field

Question 7

what is potential energy

Answer 7

the stored energy that an object has due to its position

Question 8

what is the equation for gravitational potential

Answer 8

Vgrav = - GM/r

Question 9

why is the equation for gravitational potential negative

Answer 9

since the gravitational field is always attractive and they will always gain energy when moving into the field

Question 10

what does the gravitational field strength tell us

Answer 10

how quickly is the potential changing over distance

Question 11

what is the equation that links gravitational field strength and gravitational potential

Answer 11

g = -dV/dx

Question 12

what is the equation for energy using Vgrav

Answer 12

E= m x Vgrav = m x g x dx which is gravitational energy and this is since Vgrave is defined as energy per unit mass

Question 13

why are the equations for electrical field and gravitational field similar

Answer 13

because both types of fields are radial, and the constants only differs since it depends on the way that the force interacts with the universe

Question 14

what are the main differences between electrical fields and gravitational fields

Answer 14

1. an electric field van be either positive or negative, and the field can be in either direction to or from the charge
2. a charged particle can be shielded from a electrical field, but a massive particle cannot be shielded from a gravitational field
3. electromagnetic force is significantly larger than the gravitational force