1. General Physics

Question 0

Interpret speed time graph

Answer 0

Area underneath = distance travelled
Flat line = constant speed
Straight line going up/down: constant acceleration or deceleration
Acceleration not constant -> curve

Question 1

How to calculate speed?

Answer 1

Total distance / time taken

Unit: m/s

Question 2

Interpret distance- time graph

Answer 2

The slope= speed
The steeper the slope the grater the speed
Flat line= stop
Curve up= slowing down and vice versa

Question 3

What is acceleration

Answer 3

The change of velocity per second

Unit: m/s2

Question 4

How to calculate acceleration

Answer 4

Change in velocity / time taken for the change

Question 5

Acceleration of free fall for a body near to the earth?

Answer 5

Constant acceleration

Question 6

What is velocity?

Answer 6

Speed in given direction

Question 7

What happen to the motion of a falling body

Answer 7

Object are slow down by air resistance
Air resistance gets bigger as accelerate
Once air resistance = force of gravity, the object has reached terminal velocity
Object stay at a constant velocity

Question 8

What is terminal velocity

Answer 8

When a free falling body air resistance force and gravity force is equal and the object will stay at a constant velocity.

Question 9

What is mass?

Answer 9

A measure of the amount of matters a body contains

Question 10

What is inertia

Answer 10

An object’s resistance to a change in its motion

The greater the mass, the more inertia it has

Question 11

How to calculate weight?

Answer 11

1kg = 10N

Question 12

What is density

Answer 12

How tightly packed matter is and the amount of mass in a given space

Question 13

How to calculate density?

Answer 13

Mass/ volume

Question 14

What is the density of water and when does an object sink in water?

Answer 14

Density of water= 1g/cm3

Density of object > density of water => sink

Question 15

How to measure volume of a irregular object?

Answer 15

Put the object into measuring cylinder with water. When you add the object, it displaces the waters, making the water level rises
The rise= volume of object

Question 16

What is the effect of force?

Answer 16

Change in size, shape, speed or direction

Question 17

What is elastic

Answer 17

When an object regains its original shape when the force that deform it are removed -> it is elastic

Question 18

What is elastics limit?

Answer 18

The limit to which an object can be stretched without being permanently extended

Question 19

What is hooke’s law?

Answer 19

F=kx

K is spring constant, extension is directly proportional to the weight

Question 20

What is the name when the force no longer directly proportional to the extension?

Answer 20

Limit of proportionality

Question 21

What is resultant force?

Answer 21

A single force that has the same effect as all the forces acting on the object

Question 22

What happen when resultant force =0

Answer 22

The object remain at rest if it was already at rest

Continue to move at the same speed and in the same direction if it was already moving

Question 23

How to calculate force?

Answer 23

Mass x acceleration

Question 24

Describe circular motion

Answer 24

An object moving around a circular path is acted by a resultant force which is directed towards the cent of the circle The resultant force is called the centripetal force

Question 25

What is moment?

Answer 25

Turning force

Question 26

What is moment of the force

Answer 26

The turning effect of the force Measured in Newton Can be either clockwise or anticlockwise

Question 27

How to calculate moment?

Answer 27

Force x perpendicular distance to pivot Unit Nm F x d

Question 28

Describe an object in equilibrium

Answer 28

No resultant force on it | No resultant turning force on it

Question 29

Describe the principal of moment

Answer 29

For an object in equilibrium, the sum of all the clockwise moment about any point = the sum of all anticlockwise moments about that point

Question 30

Where is the centre of mass of a suspended object in equilibrium

Answer 30

Directly below the point of suspension

Question 31

How to increase the stability of an object

Answer 31

Making its base as wide as possible and its center of mass as low as possible

Question 32

Description of kinetic energy and example

Answer 32

Energy of an object due to its motion | Eg. Vehicle in motion has kinetic energy

Question 33

Description of GPE and example

Answer 33

Energy of an object due to its position | Eg. Book lofted up gains gravitational potential energy

Question 34

Description of chemical energy and example

Answer 34

Energy stored in a substance and released when chemical reactions take place Eg car battery

Question 35

Description of elastic stain energy and examples

Answer 35

Energy stored in an elastic object when we stretch or squash it Eg stretched spring

Question 36

Description of nuclear energy and examples

Answer 36

Energy releases when the nucleus of an atom splits or disintegrate Eg a uranium fuel rod in a nuclear reactor

Question 37

Description of internal energy and example

Answer 37

Energy of an object due to the internal motion and position of its molecule Eg. Magnetized object or a hot object

Question 38

Description of electrical energy and example

Answer 38

Energy transferred by an electric current | Eg electric heater switched on

Question 39

Description of light energy and example

Answer 39

Energy transferred by light | Light from a torch

Question 40

Description of sound energy

Answer 40

Energy transfer by sound waves

Question 41

Describe the principle of conservation of energy

Answer 41

The total amount of energy before and after the change is the same Energy cannot be created or destroyed

Question 42

Equation calculating work done

Answer 42

Work done = force x distance | Unit is joules

Question 43

Calculation of KE

Answer 43

1/2 x mass x velocity

Question 44

Calculation of GPE

Answer 44

Mass x gravity x height

Question 45

What is renewable energy

Answer 45

Natural source of energy which can be replaced and be used over and over again - inexhaustible

Question 46

What is non renewable energy ?

Answer 46

Natural sources which cannot be replace and so once using it, no more use in the future -> exhaustible

Question 47

How to calculate efficiency

Answer 47

Useful energy output / energy input x 100

Question 48

What is work done? It's unit?

Answer 48

Whenever a force makes sth move Unit is joules When work is done, energy is being converted to another form

Question 49

What is power? And its unit

Answer 49

The rate at which work is done | Watt

Question 50

How to calculate power

Answer 50

Work done / time taken

Question 51

What is pressure

Answer 51

A force acting on unit area

Question 52

How to calculate pressure and its unit?

Answer 52

Force / area | Unit is pascal

Question 53

How to calculate pressure in liquid

Answer 53

Height x density x gravity