Main Focuses Flashcards
1
Q
What is a scalar quantity
A
Only magnitude
no direction
2
Q
What is a vector
A
Both magnitude and direction
3
Q
What is a force
A
A PUSH or a PULL that acts on an object due to an INTERACTION with another object
4
Q
Is a force a vector or scalar
Why?
A
VECTOR
Both direction and magnitude
5
Q
Unit for force
A
N
6
Q
What is contact force
A
Two object PHYSICALLY TOCHING
7
Q
What is a non-contact force
A
Two object PHYSCICALLY SEPERATED
8
Q
What is mass
A
The amount of MATTER that an object has in it
9
Q
Unit of mass
A
Kg
10
Q
Is mass scalar or vector
A
Scalar
11
Q
Does the mass change on the moon
A
No
12
Q
What is weight
A
The FORCE acting on an object due to GRAVITY
13
Q
Does the weight of an object change on the moon
Why?
A
Yes
Different gravitation field strength
14
Q
The weight and mass of an object are
A
DIRECTLY PROPORTIONAL
15
Q
How to determine weight instrument
A
Newtonmeter
16
Q
What is the center of mass
A
The weight of an object can be considered to act from a single point
17
Q
What is resultant force
A
The resultant force is a SINGLE force that is the SAME EFFECT as all the original forces together
18
Q
If the force are the same the resultant force is
A
0
19
Q
What shape is a vector diagram
A
Parallelogram
20
Q
What shape is a scaled vector diagram
When is this one used
A
Square
When you what the horizontal and vertical force
21
Q
1 Newton meter of work is
A
1 joule
22
Q
Work done is measured in
A
Joules
23
Q
The distance must be
A
In the line of action of the force
24
Q
What is an elastic object
A
Will always RETURN spot their original length or shape when the FORCES ARE REMOVED
25
How many force to change and objects shape
2 or more
26
What is elastic deformation
When an objects shape is change but it then return to original shape
27
What is an in elastic material
When a change is made too it's shape it does not return to its original shape
28
At what angle is a force inside a container
90
29
When is pressure created
When particles collide with a surface they exert a force
30
Pressure equation units
Force. N
Pressure Pa
Area meters
31
Why does a bag expand in space
The air pressure inside the bag is greater then the air pressure outside the bag
Because cabin pressure is lower then at ground level
32
In a container with holes why does the bottom hole squirt the furthest
Under the most pressure because more water particles above it greater weight
33
What is density of a liquid measure in
Kg/m3
34
A cube in water where is the pressure most
| Explain upthrust
The bottom is at a greater depth for experiences more pressure
So there is a larger for on the bottom of the object rather then the top
Resultant force upward
Upthrust
35
What must there be an order for an object floats
The upthrust must be equal to the objects weight
36
What happens if the upstairs is less than the object
It sinks
37
Why would you put an object in water why does is the height of the water raise
Displacement
38
What is the size of the upthrust equal to
The weight of water displaced by the object
39
How can an object float
If an object can displace its own weight of water then the upthrust will be equal to the objects weight
And float
40
What happens if the object is less dense than water
The object only has to displace a small volume of water before the weight of the water displaced equals the weight of the object
41
What happens if it has the same density as water
Displace it's own volume of water
In order for the weight of water to equal the weight of the object
The upthrust equals the weight of the object and the object floats
42
What happens if an object is more dense then water
Cannot displace the volume of water equals to its weight
| The weight of the object is greater than the upthrust so it sinks
43
Distance is in
Meters
44
Time is in
Seconds
45
What is normal walking speed
1.5 m /S
46
Running speed
3 m/s
47
Cycling speed
6 m / s
48
Car on main road speed
13 m/s
49
Train in uk
50 m/S
50
Aeroplane speed
250 m/s
51
Speed of sound
330 m/s
52
What is velocity
Speed in a given direction
53
How to calculate velocity
Same as speed
| Just add direction
54
Velocity in a circle
Even though constant speed the direction is constantly changing so the velocity is constantly changing
55
Distant time graph flat line
They have stopped
56
How to find speed on distance time graph
Gradient
57
How to fine speed at given points
Draw tangent
58
What is acceleration
The change is velocity in a given time
59
Unit of acceleration
M/s2
60
On a velocity time graph
a flat line
Diagonal-Upward -Downward
Constant velocity
Accelerating
Decelerating
61
How to find distance on velocity time graph
Area under graph
62
If you can't make nice shapes under graph what do you do
Count number of full squares + roughly
| Then multiply by the value of 1 square
63
Skydiver acceleration
Initially force of gravity causes acceleration
As the diver falls experience friction with air particles ( air resistance)
As the speed increases so does the friction
Then stops accelerating and move at constant velocity ( terminal velocity)
64
If an object experiences greater friction what happens to velocity
If an object experiences a greater force of friction due to the shape they will have a lower terminal velocity
65
What do all moving objects have
Momentum
66
What is the momentum of an object that's not moving
Zero
67
What is the conservation of momentum
In a close system the total momentum before an event is equal to the total momentum after an event
68
Explain how firing cannonball conserves momentum
Initially both cannonball and Canon have a velocity of zero
When the Canon fires the cannonball is moving at a very large velocity
So the cannonball has a momentum in the forward direction
At the same time the Canon recoils back backwards direction so has momentum backwards
The backwards and forward momentum equals the total amount of zero
69
Why is there huge force during a car crash
The momentum of the passengers falls from a large amount to 0 in a short period of time
70
How to reduce the force ( to do with momentum)
Increase the time taken to stop slows down the rate of change of momentum which reduces the force
71
What do all waves do
Transfer energy
72
Transverse
The Oscillations are perpendicular to the direction of energy transfer
73
Longitudinal
The oscillations are parallel to the direction of energy transfer
74
What do all longitudinal waves need
A medium to travel through
75
Where is the amplitude of a wave
It's between the top of the wave to the middle
76
Where is the wavelength of a wave
It's between the two tips of the wave or the two troughs
77
How to get a wavelength on a longitudinal wave
Between two compressions or two refractions
78
What is the frequency of a wave and the unit
The frequency is the number of waves per second
| Hz = 1 Wave per second 
79
What is the period of a wave
| Units
A time for one way to pass a point
Time in seconds
frequency and hz

80
Unit for. Distance in the wave equation
Meters
81
What are the three things that can happen to the way when it passes into a different median
Transmitted
Absorb
Reflect
82
Angle of incidence is =
Angle of refraction
83
Why is an image virtual
Not made of real days of light
84
What type of wave is sound
Longitudinal
85
How does the microphone work
Sound waves hit the cone causing it to vibrate
| This is then converted into electrical signals
86
Frequency of human hearing
20 Hz to 20,000 Hz
87
Relationship between frequency and pitch
High frequency high pitch
| Low-frequency frequency low
88
Relationship between amplitude and sound
Small amplitude quiet sound
| Large amplitude loud sound
89
Where can soundwaves not travel
No vacuum because there are no particles sand waves move by vibrating particles
90
What is reflected sound wave called
Echo
91
What is an ultrasound
Is a sound with waves higher frequency than human hearing
| Above 20,000 Hz
92
Key when calculating distance by ultrasound
Half it
93
S wave
Which
Properties
Speed
Transverse
Solids only
Slower then P waves
94
P wave
Type
Property
Speed
Longitudinal
Solid and liquid
Faster then S waves
95
Pattern of p and S waves in the earth
S waves cannot pass through a liquid that is the S way Shadowzone which shows that the core is liquid
P wave however can pass through the core so core is liquid

96
Why do I get P-wave shadow zones
P-waves are faster in solids than in liquids
this means they slow down into the liquid outer core
This cause them to refract
They also refract when they leave the court disproves the core liquid
97
What is a moon
Natural satellite
98
What is a galaxy
Massive group of stars
99
Formation of a star
Nebula - cloud of dust and gas
Protostar- gravity cause dust and and gas to collapse - rise to million of degrees
Star - when hydrogen nuclei join together to from helium ( nuclear fusion)- release lots of energy
100
When is the star equilibrium
When the force of gravity acting inwards is equal to the force of fusion energy acting outwards
101
Life cycle of a star same size as sun
1) earlier flash card to star
2) hydrogen runs out The outward force due to fusion is less than the inward force of gravity
3) This causes the collapse of the star which cause it's temperature to increase
4). Helium nuclei fuse together to create heavier elements
3) The start expands to form a red giant
5). When it stops for using helium it becomes a white dwarf and then it cools down to black dwarf

102
Life cycle of a star bigger than our sun
1) leave the main sequence and expand to become red supergiant
2) helium nuclei fuse together to create heavier elements
3) when it stops carrying out nuclear fusion explodes called a supernova
3) The temperature of a supernova is high enough to produce and it's heavier than iron
4) The elements are then distributed in the universe
5). Neutron star or black hole

103
How do you planets actually orbit
Elliptical orbit
104
What holds the Earth in its orbit
Gravity
105
How often did geostationary satellite orbit
Every 24
106
Why is the velocity constantly changing in a satellite
The force of gravity causes the object to change direction but not speed because the object is constantly changing direction is constantly changing velocity because velocity is a vector
107
What happens if the speed of a satellite increases
If the speed increases in the radius of its orbit decreases
At higher speed a greater force of gravity in needed to prevent it flying off
Closer to the Earth the gravitational force greater
108
What does Redshift tell us
The Galaxy is moving away from each other
109
The further away the Galaxy ......that the Redshift
The further way galaxy the bigger the Redshift
110
Wave length and galaxies
The further away the galaxy the faster the speed so the greater the wavelength
111
What proof is that at a university expanding
Distant galaxies moving faster than closer galaxies
112
Why do scientist believe the universe began ( Big Bang theory )
From a small region that was hot and dense
113
Observations of what show that the rate of the expansion is increasing
Supernova
114
What do the scientist blame on the fact that they can't explain the universe
Dark matter and dark energy which we can't detect
