Question

In physics what is a field?

A) the immediate space around a charge, mass or magnet
b) a region in which something experiences a force
C) the space in which objects are able to move
D) The region between two charges, masses or magnets

Answer 1

I think its B but im not 100% positive

Answer 2

I would say C.

Answer 3

the larger the object the more field lines? is that true?

Answer 4

A field is associated with the plotting of spacetime. C is the only answer that is general enough to cover this fact.

Generally speaking, yes, the larger the object the "more" field there is.

Answer 5

B

Answer 6

... Proof, for those who disagree. http://en.wikipedia.org/wiki/Field_%28physics%29

Answer 7

Define the concept of a gravitational field?

Answer 8

It's a field that is caused due to the bump in spacetime caused by mass. Sort of hard to imagine in 3D.

Answer 9

That is by no means a definition. It's just to give you an idea.

Answer 10

A field where the acceleration of gravity acts as a force on all bodies inside. Alternatively, a field that is a geodesic, in terms of general relativity.

Answer 11

Doesn't he mean the origin of gravity?

Answer 12

"The concept of a gravitational field". The field itself, not the mass. But you covered for that anyways, so I'm not worried. ;D

Answer 13

What would be the gravitational field at the midpoint between, and due to two identical planets? explain

Answer 14

Be a zero net force. Nearly impossible in reality. It would just stay in position.

Answer 15

Thanks guys! I have a few more questions :)

Answer 16

An object of mass 12kg weighs 156 N on planet X. what is the magnitude of the acceleration due to gravity on planet x

Answer 17

F = ma
a = F/m
156/12 = something

Answer 18

What LordHades said. I'm just piggybacking his medals.

Answer 19

how might this planet differ from Earth?

Answer 20

Well, its acceleration due to gravity is much higher, so it's probably of a greater mass.

Answer 21

And you;ll weigh heavier there.

Answer 22

12*9.81= 117.6N

Answer 23

Note that I'm talking about weight not mass.

Answer 24

that would be on earth, so you are lighter on earth

Answer 25

yes,

Answer 26

The Earth has a mass of 6x10^24kg and a diameter of 12,765 km. A 500kg satellite experiences a gravitational acceleration of 0.4 ms^-2 in its orbit. What is the altitude of the satellite?

Answer 27

M = 6 x 10^24
re = 6382.5
m = 500
ac = 0.4

ac = v^2/r
r = v^2 / ac -------->1

GMm/r^2 = mv^2/r ------------>2

From 1 and 2,

Solve for 'v' and then get 'r'

Should work I think, tell me if I messed up somewhere.

Answer 28

List of possible answers
a) 2.53 x10^7 m
b) 3.16 x 10^7 m
c) 2.80 x 10^8 m
d) 2.86 x 10^8m

Answer 29

From here on it's just calculations and algebra, nothing difficult.

Answer 30

At what altitude would a 1000kg satellite be to experience the same gravitational acceleration? Explain

Answer 31

You could use the exact same formulae, just need to rearrange the variables.

Answer 32

I dont have a calculator with me :(

Answer 33

Doubling the mass, yet keeping the acceleration the same, is multiplying both sides of the equation by 2.

Answer 34

The force vector of the satellite, the one we're concerned with, doubles, right?

Yeah. The mass of the satellite also doubles.

Answer 35

do you know about the Lagrange points in a feild?

Answer 36

no... what are they?

Answer 37

the stable points,
for example in the sun earth system there are 5 stable points (places where gravitational attraction is balanced)