Physics Chapter D

What is a Field?

a mathematical concept that explains how and object is able to exert a force on another object even though they aren't in contact.

What is the quantity of a field?

Charge

What do the forces of gravitation and electrostatics depend on?

1/distance² a.k.a Inverse square

What are the types of fields?

Gravity, Electric & Magnetic

What happens when a charge moves through and electrical field?

Energy is transferred to or from the field system

What happens when a force is acted upon a particle?

The particle moves with a displacement component in the direction of the force then work is done.

What is potential energy?

a measure of energy stored within the field due to presence of an object.

What is force proportional to?

force is proportional to 1/distance²

What is gravitational field strength defined as?

Gravitational field strength = Gravitational force/mass

What are the units for gravitational field strength?

N kg^-1

Gravitational field strength is a vector or scalar?

Vector

Gravitational field strength

a point when the force per unit mass experienced by a small point mass placed at that point.

gravitational field strength is equivalent to

acceleration due to gravity

What is the field strength defined as?

force acting on the test object/ size of the test object.

What is the value for the Universal gravittaional constant?

6.67 × 10ˆ-11 Nmˆ2 kgˆ-2

Laws that depend on 1/rˆ2 are also known as

Inverse square

What is newton's law of gravitation?

When the distance between the two masses is doubled without changing mass, then the force between the masses goes down to one-quarter of its original value.

What is the consequence of a force that follow inverse square?

the force becomes weaker as the distance increases, but it never becomes zero at any finite distance.

What is a field line?

It gives direction in which a gravitational force acts on a mass placed on the field line.

What is the arrangement of the gravitational field

Radial

What is the centre of mass?

this is the point about which the distribution of mass in an object is the same in all directions.

What is centre of gravity?

is the point at which all the weight of an object appears to act.

What is Kepler’s first law?

Planets move in an elliptical orbit

What is Kepler’s second law?

an orbiting objects will take the same amount of time to travel between two points

What is Kepler’s third law?

the square of the planet’s orbital time is proportional to its average distance from the star cubed

What does the force of gravity equal to?

Centripetal force