Physics paper one

Question 1

The centre of mass

Answer 1

The point at which all the mass of an object seems to be concentrated.

Question 2

The stability

Answer 2

How easily an object topples over

Question 3

Hypothesis

Answer 3

The higher the centre of mass of an object, the more likely it is to topple over

Question 4

The higher something is…

Answer 4

The less stability it has

Question 5

Work

Answer 5

An object is said to have done work when it transfers (uses) energy

Question 6

Work done equation

Answer 6

Work done=force x distance

Question 7

What is work done equal to?

Answer 7

The work done by an object is equal to the amount of energy that it transfers

Question 8

Moment

Answer 8

The turning effect of a force

Question 9

Moment equation

Answer 9

Moment= Force x perpendicular distance from the line of action of force to the pivot

Question 10

Levers

Answer 10

Used as force multipliers, a force multiplier exerts a greater force to the load that is applied to the lever

Question 11

Gear

Answer 11

Directly connected to the force of the engine

Question 12

The bigger the wheel,

Answer 12

it has twice the radius as a smaller wheel- it therefore has a greater moment

Question 13

Increase force

Answer 13

The second wheel has more teeth than the first one, it turns slower than the first one but with more force

Question 14

Change direction

Answer 14

When two gears mesh together, the second one always turns in the opposite direction.

Question 15

Elastic potential difference

Answer 15

The energy stored when a force is applied to an elastic object causing it to stretch or compress

Question 16

Force equation

Answer 16

spring constant x extension

Question 17

Diagonal force

Answer 17

Means part of this force is acting horizontally and part of this force is acting vertically

Question 18

Horizontal component=

Answer 18

force x cos(angle)

Question 19

Vertical component

Answer 19

Force x sin(angle)

Question 20

Kinetic energy

Answer 20

The energy in moving objects- movement energy

Question 21

Electrical energy

Answer 21

Energy in moving charges or static electric charges

Question 22

Heat energy

Answer 22

Also called thermal energy

Question 23

Elastic potential

Answer 23

stored energy in squashed or stretched objects

Question 24

Light energy

Answer 24

Also called radiant energy

Question 25

Nuclear energy

Answer 25

Stored in the nuclei of atoms

Question 26

Gravitational potential

Answer 26

Energy stored in raised objects

Question 27

Internal energy

Answer 27

Contained in a thermodynamic system

Question 28

Chemical energy

Answer 28

Stored energy in batteries, food and fuel

Question 29

Strain energy

Answer 29

Released when atoms in a molecule rearrange themselves in a chemical reaction

Question 30

Sound energy

Answer 30

Energy realised by vibrating objects

Question 31

Efficiency

Answer 31

The efficiency of a device is the proportion of the energy supplied that is transferred in useful ways. The efficiency can be calculated as a decimal or a percentage.

Question 32

Efficiency equation

Answer 32

useful energy out divided by Total energy in

Question 33

Switch

Answer 33

A switch used to turn a circuit on (closed) and off (open).

Question 34

Lamp

Answer 34

An electrical current heats the filament in a bulb so that it gives out light.

Question 35

Fixed resistor

Answer 35

A resistor restricts or limits the flow of electrical current. A fixed resistor has a resistance that does not change.

Question 36

Variable resistor

Answer 36

Moving the position of the slider on this resistor, changes the resistance. A variable resistor is used in some dimmer switches and volume controls.

Question 37

Thermistor

Answer 37

A thermistor can be used in thermostats or heat activated fire alarms.

Question 38

LDR

Answer 38

A LDR can be used as a sensor in cameras or automatic lights that come on when it gets dark. The resistance of a LDR depends on light intensity. At low light levels, the LDR has a high resistance. As the light intensity increases, the resistance decreases

Question 39

Semiconductor diode

Answer 39

A semiconductor diode allows current to flow in one direction only. Current will not flow in the other direction. Diodes are used to convert an alternating current into a direct current.

Question 40

Alternating current

Answer 40

An electric current that regular changes its direction and size

Question 41

Direct current

Answer 41

The movement of charge through a conductor in one direction only

Question 42

Static electricity

Answer 42

All about charges which are not free to move- causes them to build up in one place often needs with a spark

Question 43

Build up of static electricity

Answer 43

Caused by friction

Question 44

How is static electricity formed

Answer 44

Insulating objects are rubbed together, negatively charged electrons will be scraped off one and dumped on the other, leave a positive static charge and an equal negative on an other

Question 45

Electrostatic charges formed by

Answer 45

Only formed by the movement if electrons - positive don't move!

Question 46

Two electrically charged objects

Answer 46

When brought close together they exert a force on one another

Question 47

Opposite electric charges

Answer 47

Are attracted to each other

Question 48

Same electric charges

Answer 48

Will repel each other

Question 49

Closed systems

Answer 49

Systems where matter nor energy can enter or leave