Physics Grade 11

Question 1

What is kinetic energy?

Answer 1

Energy an object has because of its motion

Question 2

What is thermal energy?

Answer 2

energy contained within a system that is responsible for its temperature.

Question 3

What is specific heat capacity?

Answer 3

the thermal energy required to raise the temperature of 1kg of a substance by 1℃ or by 1K.

Question 4

What is specific latent heat?

Answer 4

he amount of energy required to change the state of 1 kilogram (kg) of a material without changing its temperature

Question 5

What is thermal equilibrium?

Answer 5

the situation when there is no net exchange of thermal energy between components of a system. i.e. the components have the same temperature and thus the average kinetic energy of the particles is the same

Question 6

What is Heat?

Answer 6

energy in the process of being transferred from one place to another due to the temperature difference.

Question 7

What is temperature?

Answer 7

a measure of the average kinetic energy of the particles that make up a substance.

Question 8

What is internal energy

Answer 8

the total microscopic kinetic energy, and microscopic potential energy of the particles in a system. It does not include macroscopic energy.

Question 9

what is the concept of proportionality

Answer 9

Energy put into different substances does not result in the same temperature rises

Question 10

why does temperature in a system remain the same during a change of state?

Answer 10

The addition of thermal energy does not go into changing the kinetic energy of the particles but into changing the potential energy

Question 11

what is specific latent heat of vaporization

Answer 11

The amount of thermal energy required to change 1kg of a liquid at its boiling point into a vapor.

Question 12

What is the zeroth law of thermodynamics

Answer 12

If two bodies are in thermal equilibrium with a third body, they are in thermal equilibrium with each other’.

Question 13

what is the first law of thermodynamics, Work done on the system?

Answer 13

The increase in the internal energy of a system is equal to the amount of heat added to the system, plus the amount of work done on the system.

Question 14

What is the first law of thermodynamics, work done by the system?

Answer 14

The increase in the internal energy of a system is equal to the amount of heat added to the system, minus the amount of work done by the system.

Question 15

What is the first law of thermodynamics?

Answer 15

The internal energy of a system has to be equal to the work that is being done on the system, plus or minus the heat that flows in or out of the system and any other work that is done on the system.”

Question 16

what is thermal efficiency?

Answer 16

Thermal efficiency is the ratio of useful work out of a machine or in a process, total energy expended or heat taken in

Question 17

Why do protons repel each other

Answer 17

opposite charges attract and the same charges repel

Question 18

what is the strong nuclear force

Answer 18

holds protons and neutrons together in the nucleus.

Question 19

explain natural radioactive decay

Answer 19

outside the island of stability, the nucleus undergoes natural radioactive decay and breaks apart because of the instability caused by the competing electrostatic force and the strong nuclear force.

Question 20

what is alpha radiation

Answer 20

a stream of particles each consisting of two protons and two neutrons emitted from the nucleus of some radionuclides.

Question 21

what is alpha decay

Answer 21

Alpha decay occurs when there are too many protons and neutrons (i.e. too much mass).

Question 22

beta negative decay

Answer 22

when there is a surplus of neutrons for how many protons there are

Question 23

Beta positive decay

Answer 23

Beta positive decay occurs when there are too many protons in the nucleus for the number of neutrons.

Question 24

gamma decay

Answer 24

a release of energy that originates from within the nucleus.

Question 25

what is a nuclear decay series

Answer 25

A decay series refers to a sequence of nuclides formed by successive radioactive decays until a stable decay product (the last nuclide in the series) is formed.

Question 26

What is a half life

Answer 26

the time for half the radioactive nuclei in any sample to undergo radioactive decay; or, The amount of time taken for the number of nuclei present in a sample at a given time to exactly halve.

Question 27

What is artificial transmutation

Answer 27

an induced nuclear reaction by means of bombardment with a projectile of fundamental particles

Question 28

nuclear fission

Answer 28

An artificial nuclear reaction in which a large unstable nucleus splits, forming two (or more) smaller, more stable nuclei and releases energy and neutrons.

Question 29

Nuclear fusion

Answer 29

Nuclear fusion is the process by which two light atomic nuclei combine to form a single heavier one while releasing massive amounts of energy.

Question 30

mass defect

Answer 30

Mass defect is defined as the difference between the mass of the atom and the sum of the masses of its component protons, neutrons and electrons

Question 31

conservation of charge

Answer 31

The net amount of charge produced in any transfer process is zero  the net amount of charge lost by one object is gained by the other.

Question 32

Electrical potential difference

Answer 32

Potential difference (p.d.; ∆V) is the difference in electric potentials between two points in an electric field.

Question 33

Electric current

Answer 33

the rate of motion of electric charge carriers from one part of a conductor to another.

Question 33

Electrical resistance

Answer 33

a measure of its opposition to the flow of electric current.

Question 34

Ohms law

Answer 34

Electric current is proportional to voltage and inversely proportional to resistance.

Question 35

scalar

Answer 35

quantities containing only magnitude

Question 36

vector

Answer 36

quantities containing magnitude and direction

Question 37

Displacement

Answer 37

it is the object's overall change in position.

Question 38

velocity

Answer 38

the rate at which an object changes its position

Question 39

Acceleration

Answer 39

rate of change of an object's velocity with respect to time

Question 40

Newtons first law

Answer 40

an object maintains its state of rest or constant velocity motion unless it is acted on by an external unbalanced force.

Question 41

Newtons 2nd law

Answer 41

the acceleration of an object is in the direction of the net external force acting on it and proportional to the size of the force and inversely proportional to the mass

Question 42

Newtons 3rd Law

Answer 42

for every action there is an equal and opposite reaction’, but this implies that the reaction follows the action.

Question 43

Momentum

Answer 43

Momentum is the quantity of motion of a moving body

Question 44

Impulse

Answer 44

the effect of force acting over time to change the momentum of an object.

Question 45

law of conservation of momentum

Answer 45

For two objects colliding in an isolated system, the total momentum before and after the collision is equal

Question 46

elastic collisions

Answer 46

A collision where kinetic energy and momentum are conserved

Question 47

inelastic collisions

Answer 47

A collision where momentum is conserved but kinetic energy is not.

Question 48

kinetic energy

Answer 48

Energy due to the motion of an object, including the motion of particles in a substance

Question 49

gravitational potential energy

Answer 49

Energy stored in an object due to its position relative to another object to which it is attracted by the force of gravity

Question 50

mechanical waves

Answer 50

Waves that require an elastic medium (e.g. air or water; not in a vacuum) for the transfer of energy.

Question 51

Reflection

Answer 51

Reflection is the process where incident waves at a boundary change direction returning into the same medium.

Question 52

Superposition

Answer 52

When two or more waves overlap in space, the resultant wave is the algebraic sum of the individual waves

Question 53

Standing wave

Answer 53

those with stationary vibration patterns formed due to the superposition of waves with particular frequencies.

Question 54

Refraction

Answer 54

The process when incident waves at a boundary change direction and speed when passing into another medium.

Question 55

Diffraction

Answer 55

The process by which waves either bend behind a barrier or the wavefront is broken up into many small sources.

Question 56

Resonance

Answer 56

Resonance occurs when a vibrating object or external force causes another system to oscillate with greater energy at a particular frequency.

Question 57

Natural frequency

Answer 57

The frequency at which an object tends to vibrate with when hit, struck, plucked, strummed or somehow disturbed is known as the natural frequency of the object.

Question 58

Intensity

Answer 58

the average rate of flow of energy per unit area’.

Question 59

snells law

Answer 59

When light travels from one medium to another, the ratio of the sine of the angle of incidence to the sine of the angle of refraction is equal to the refractive index (n).