P1 Defenitions

Question 1

Define a random error and a systematic error

Answer 1

A random error is a one off error
A systematic error is an error that occurs every time a reading is taken

Question 2

Give a definition for accurate and precise

Answer 2

Accuracy is the closeness of a measured value to the true value
Precision is the closeness of agreement between measured values which are obtained by repeated measurements

Question 3

Give a definition for true value

Answer 3

This is the value that would be obtained by an ideal measurement that has no errors at all

Question 4

Define terminal velocity

Answer 4

The maximum speed reached by an object when the forward/downwards force is balanced by resistance forces

Question 5

Give a definition for couple

Answer 5

Two forces that are equal by act in opposite direction and do not act in the same straight line

Question 6

Define work done

Answer 6

The product of the force and the distance moved in the direction of this force

Question 7

Give a definition for 1 joule

Answer 7

The work done when a one Newton force moves an object a distance of 1 m in the direction of the force

Question 8

Give a definition for power

Answer 8

The rate of energy transfer

Question 9

Give a definition for spring constant

Answer 9

The force required to extend a material by one meter

Question 10

Define ductile and polymeric

Answer 10

Ductile material shows a lot of plastic deformation before it breaks and polyamory materials are made up of molecular chains

Question 11

State the principle of the conservation of momentum

Answer 11

In a closed system, the total momentum after a collision is equal to the total momentum before the collision provided no external forces act

Question 12

Define internal energy 

Answer 12

The sum of the randomly distributed kinetic and potential energies of all the atoms in a substance

Question 13

Define absolute zero

Answer 13

The temperature at which the kinetic energies of the atoms in a substance is zero

Question 14

Define specific heat capacity
Specific latent heat of fusion
Specific latent heat of vaporisation

Answer 14

Specific heat capacity is the energy required to raise the temperature of a 1 kg kilogram substance by one Kelvin
Specifically latent heat of fusion is the energy required to change the state of 1 kg of substance from solid to liquid without changing its temperature
Specifically in heat of vaporisation is the energy required to change the heat of 1 kg of substance from liquid to gas without a change in temperature

Question 15

What is an ideal gas?

Answer 15

A gas in which the ideal gas laws apply

Question 16

What is the RMS speed?

Answer 16

The square root of the mean of the squares of the speeds of a particle in a substance

Question 17

What is the angular velocity?

Answer 17

The rate of change of an angle

Question 18

What is the centripetal force?

Answer 18

A force that acts perpendicular to motion of an object and towards the centre of the circular path followed by the object

Question 19

What is required for simple harmonic motion?

Answer 19

The acceleration of the object must be directly proportional to the displacement from its equilibrium position but acts in the opposite direction to the displacement

Question 20

What does isochronous mean?

Answer 20

The time period is constant

Question 21

What is the natural frequency?

Answer 21

The frequency at which an object would oscillate if they were initially displaced and left to oscillate freely

Question 22

What is resonance

Answer 22

When the driving frequency is equal to the natural frequency of the oscillator therefore maximum energy is transferred to the oscillator and the amplitude increases with each cycle

Question 23

Explain damping

Answer 23

When an external force act on an oscillator which will reduce the amplitude over overtime

Question 24

Define gravitational field strength

Answer 24

The gravitational force acting on an object per unit mass

Question 25

What is a gravitational field?

Answer 25

A region of space in which an object with mass would experience a force

Question 26

State Newton’s law of gravitation

Answer 26

The gravitational force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the separation between their senses of mass

Question 27

State all three Kepplers laws

Answer 27

Capless first law is that the orbit of a planet is an ellipse with the sun at one focus Second law is that a line segment joining a planet and the Sun will sweep out equal areas and equal time intervals Third law is for a planet orbiting the Sun T squared is proportional to our cubed

Question 28

What is a geostationary satellite?

Answer 28

A satellite that remains above the same point of the earth surface therefore is always an orbit above the equator and rotates in the same direction as earth and has an orbital period of 24 hours

Question 29

What is gravitational potential?

Answer 29

The work done per unit mass to move an object from infinity to that point

Question 30

Define escape velocity

Answer 30

The velocity and object must have in order to overcome the gravitational attraction of a planet and escape its pull

Question 31

Describe the characteristics of a planet

Answer 31

It is an orbit around a star and has a large enough mass for gravity to be pulled it into a spherical shape and must have played its orbit of other objects and there is no fusion taking place

Question 32

What is a planetary satellite?

Answer 32

An object in a circular orbit around a planet

Question 33

What is a comet?

Answer 33

It is made of rock dust ice and orbit the Sun at high elliptical orbits

Question 34

What is the solar system and galaxy?

Answer 34

The solar system is a collection of planets in orbit around a star The galaxy is a collection of billions of stars

Question 35

What is electron degeneracy?

Answer 35

When electrons are squeezed together, this creates a pressure 

Question 36

What is the Chandrashekar limit?

Answer 36

This is the maximum mass of a stable white dwarf star

Question 37

What is the emission line spectrum?

Answer 37

A unique set of coloured lines against a dark background when a gas is heated

Question 38

What is an absorption line spectrum?

Answer 38

The unique set of dark lines against a continuous spectrum when light is passed through a cold gas

Question 39

What is a black body?

Answer 39

An object which absorbs all electromagnetic radiation incident upon it

Question 40

Define an astronomical unit

Answer 40

This is the average distance from the Earth to the Sun

Question 41

Define a light-year

Answer 41

The distance travelled by light in one year

Question 42

What is a parsec?

Answer 42

A star which is one parsec away will have a parallel angle of one arch second

Question 43

Describe the Doppler effect

Answer 43

This is when the observed frequency is different from the source frequency when it moves relative to the observer

Question 44

What is Hubble’s law?

Answer 44

The velocity of a distant galaxy is directly proportional to its distance from earth

Question 45

What is the cosmological principle? And defined the terms used.

Answer 45

The universe homogeneous and isotropic and the laws of physics are universal Homogeneous is when matter is distributed evenly and the density of the universe is constant Isotropic is that the universe looks the same in all directions

Question 46

What is The Big Bang Theory?

Answer 46

That the universe started with everything in a single hot dense point which suddenly expanded outwards

Question 47

What is dark matter?

Answer 47

A hypothetical type of matter spread through the universe and explained the rotational speed of galaxies, but that’s not emit or absorb electromagnetic radiation