Gravitational Electric and Magnetic Fields

Question 1

What is the universal law of gravitation

Answer 1

• newton stated that there is a gravitational attraction between any two objects depending on their masses and distance between

Question 2

What is a gravitational field

Answer 2

• it is an area or influence and a collection of vectors

Question 3

What is gravitational field strength?

Answer 3

• it is the gravitational force acting on each kg of mass . It’s équivalant to the acceleration due to gravity

Question 4

Why do astronauts seem like they float

Answer 4

• they are in the state of free fall : gravity causes all objects to fall at the same rate which results in an appearance of weightlessness aka microgravity

Question 5

Describe how satellites can travel

Answer 5

• They are projectiles meaning the only force acting on them is gravity
• They are constantly falling around the earth

Question 6

What is electric force

Answer 6

• the repulsive or attractive force between two charge objects
• Proportional to charge and inversely to their distance
• COULOMBS (C) AND DIRECTION

Question 7

What are negative and positive charges caused from

Answer 7

NEGATIVE - caused by a EXCESS of electrons
POSITIVE - caused by a SHORTAGE of electrons.

Question 8

What are electric fields?

Answer 8

Defined as the force per unit charge
- depend on size and distance of the charges.
- they’re VECTOR quantities

Question 9

Describe magnetic poles (3 points)

Answer 9

1. magnetic poles only occur in pairs. (N and S)
2. they exert forces on each other from a distance creating magnetic fields.
3. they’re vectors so you draw them with arrows

Question 10

Explain Earths magnetic field and compasses

Answer 10

• The earth is the largest magnet which resembles a bar magnet
• The N pole of a compass lines up with earths magnetic field lines. This mean magnetic North is actually the South pole

Question 11

What causes earths magnetic fields?

Answer 11

The flow of liquid iron in earths core creates moving electric charges (called currents) which then creates magnetic field.

Question 12

What is the principle of magnetism?

Answer 12

Electric currents create magnetic fields.