G484 Definitions

Question 1

Newton’s 1st Law

Answer 1

An object will remain at rest or keep travelling at a constant velocity unless it is acted on by an external force.

Question 2

Newton’s 2nd Law

Answer 2

The net force acting on an object is equal to the rate of change of momentum. The net force and the change in momentum are in the same direction.

Question 3

Newton’s 3rd Law

Answer 3

When two bodies interact they exert equal and opposite forces of the same kind on each other.

Question 4

Linear Momentum

Answer 4

The product of an objects mass and its velocity.

Question 5

Net Force

Answer 5

The resultant of all the forces acting on an object.

Question 6

Impulse of a Force

Answer 6

The product of a force and the time for which it acts.

Question 7

Conservation of Momentum

Answer 7

In a closed system, when bodies interact, the total momentum in any specified direction remains the same.

Question 8

Perfectly Elastic Collision

Answer 8

A collision in which kinetic energy is conserved (momentum and total energy always conserved).

Question 9

Inelastic Collision

Answer 9

A collision in which kinetic energy is not conserved (momentum and total energy are conserved).

Question 10

Radian

Answer 10

The angle subtended at the centre of a circle when the arc length is equal to the radius. Pi radians equals 180 degrees.

Question 11

Gravitational Field Strength

Answer 11

The gravitational force per unit mass.

Question 12

Newton’s Law of Gravitation

Answer 12

Any two point masses attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of their separation.

Question 13

Period

Answer 13

The time taken by an object to complete one orbit or for one complete oscillation by a vibrating object.

Question 14

Geostationary Orbit

Answer 14

The orbit of a satellite which has a period of one day and is in the equatorial plane.

Question 15

Simple Harmonic Motion

Answer 15

Motion of an oscillator where acceleration is directly proportional to the displacement and is directed towards the equilibrium position.

Question 16

Displacement (in terms of shm)

Answer 16

Distance from the equilibrium position, can be positive or negative.

Question 17

Amplitude

Answer 17

Magnitude of the maximum displacement from the equilibrium position.

Question 18

Frequency

Answer 18

The number of oscillations per unit time.

Question 19

Angular Frequency

Answer 19

The rate of change of an angle expressed in radians per second.

Question 20

Phase Difference

Answer 20

The fraction of an oscillation between the vibrations of two oscillating particles, expressed in degrees or radians.

Question 21

Pressure

Answer 21

Force per unit area

Question 22

Internal Energy

Answer 22

The sum of the random distribution of kinetic and potential energies of all the atoms/molecules in a system.

Question 23

Absolute Zero

Answer 23

The temperature at which a system has minimum internal energy: equivalent to -273.15oC

Question 24

Specific Heat Capacity

Answer 24

The energy required per unit mass of a substance to raise its temperature by 1K.

Question 25

Boyle’s Law

Answer 25

The pressure exerted by a fixed mass of gas is inversely proportional to its volume, provided the temperature of the gas remains constant.

Question 26

Kepler’s 3rd Law

Answer 26

The period of a planet orbiting the Sun squared is proportional to the mean radius cubed.

Question 27

Kinetic Theory of Gases Assumptions

Answer 27

A gas consists of a large number of particles in rapid, random motion.
All collisions are perfectly elastic.
There are no gravitational forces.
No intermolecular forces exist except during collisions.
The volume of the particles is negligible compared to the volume of the container.