Definitions G484

Question 1

Resonance

Answer 1

The build up of a large amplitude oscillation when the frequencies of vibrating objects match

Question 2

Phase

Answer 2

Whether a substance is a solid, liquid or gas

Question 3

Ideal gas

Answer 3

A gas that has internal energy only in the form of kinetic energy

Question 4

Specific latent heat of fusion

Answer 4

The quantity of energy required per unit mass to change a substance from a solid to a liquid at a constant temperature

Question 5

Displacement

Answer 5

The distance of the body from an equilibrium position

Question 6

Amplitude

Answer 6

The maximum displacement

Question 7

Frequency

Answer 7

The number of oscillations per unit time

Question 8

Angular frequency

Answer 8

The product of 2pif or 2pi/period

Question 9

Specific latent heat of vapOrisation

Answer 9

The quantity of energy required per unit mass to change a substance at constant temperature from a liquid into a vapour

Question 10

Ideal gas temperature

Answer 10

For a fixed mass of an ideal gas at constant pressure, it’s volume is proportional to the ideal gas temperature in kelvin.

Question 11

One mole

Answer 11

The Avogadro constant is the number of particles in one mole.

Question 12

Boltzmann constant

Answer 12

1.3807*10^-23JK^-1 the gas constant for a single molecule

Question 13

Boyle’s law

Answer 13

Pressure is inversely proportional to volume for a fixed mass of gas at constant temperature

Question 14

The Newton

Answer 14

The force which gives a mass of one kg an acceleration of one ms^-1

Question 15

Gravitational field strength

Answer 15

Force per unit mass at a point in a gravitational field.

Question 16

Newton’s first law

Answer 16

A body will remain at rest or continue to move with constant velocity unless acted on by a force

Question 17

Newton’s second law

Answer 17

Force is proportional to the rate of change of momentum

Question 18

Newton’s third law

Answer 18

When one body exerts a force on another, the other body exerts an equal and opposite force on the first body.

Question 19

Principle of conservation of linear momentum

Answer 19

Total momentum is constant for a closed system

Question 20

Inelastic collision

Answer 20

Some loss of kinetic energy during the collision. The coefficient of restitution is less than one.

Question 21

The kilowatt-hour

Answer 21

The energy used by a 1kW device in 1h

Question 22

Internal energy

Answer 22

Sum of randomly distributed kinetic energy and potential energy of molecules

Question 23

Impulse of a force

Answer 23

Force x time for which the force acts. (Change in momentum)

Question 24

Specific heat capacity

Answer 24

Energy required to raise the temperature of a unit mass of a substance by a unit temperature rise.

Question 25

Equilibrium

Answer 25

The resultant force is zero.

Question 26

Simple harmonic motion

Answer 26

Acceleration is proportional to displacement and is directed in the opposite direction to the displacement, towards the equilibrium position.

Question 27

Thermal equilibrium

Answer 27

No net heat flow between objects

Question 28

Perfectly elastic collision

Answer 28

A collision with no loss of kinetic energy. Coefficient of restitution = 1

Question 29

Linear momentum

Answer 29

Mass x velocity

Question 30

Kepler's third law

Answer 30

The cube of the planet's mean radius of its orbit is proportional to the square of the orbital period.

Question 31

Centripetal acceleration

Answer 31

For an object travelling in a circle of radius r with constant speed v, a is given by a=v^2/r in a direction towards the centre of the circle.

Question 32

Field

Answer 32

The region in which a force operates

Question 33

One radian

Answer 33

The angle subtle dead at the centre of a circle by an arc of length equal to the circle's radius.

Question 34

Period

Answer 34

For circular motion, the time taken to complete one revolution. v=Circumference/time

Question 35

Newton's law of gravitation/ gravitational force

Answer 35

Between two bodies, it's directly proportional to the product of their masses, and inversely proportional to the square of the distance between them squared. F=(-GMm)/r^2

Question 36

Period of a planet

Answer 36

The time taken for one complete orbit of the sun

Question 37

Damping

Answer 37

Deliberately reducing the amplitude of an oscillation

Question 38

Impulse

Answer 38

The expression F/\t. It equals the change in momentum of a body. It is the area beneath a force-time graph