1
Q
What is a vector quantity
A
Quantity that has magnitude and direction
2
Q
Vector quantities
A
Force
Velocity
Displacement
Acceleration
Momentum
3
Q
What is a scalar quantity
A
Quantity that only has magnitude, no direction
4
Q
Scalar quantities
A
Speed
Distance
Mass
Temperature
Time
5
Q
What are vectors represented by
A
Arrow
- length of it = magnitude
- direction of it = direction
6
Q
What is a force
A
A push or pull on an object that is caused by it interacting with something
7
Q
What is a contact force
A
When two objects have to be touching for a force to act
8
Q
What is a non-contact force
A
Objects do not need to be touching for the force to act
9
Q
Examples of contact forces
A
Friction
Air resistance/drag
Tension
Normal contact force
Upthrust
Buoyancy
10
Q
Examples of non-contact forces
A
Magnetic
Gravitational
Electrostatic
Electrochemical
11
Q
What is gravitational force
A
Force of attraction between masses
12
Q
What is mass
A
The amount of ‘stuff’ in an object. This will always be the same no matter where you are
13
Q
What is weight
A
Force acting on an object due to gravity. Close to earth this force is caused by the gravitational field around the earth
14
Q
What does the weight of an object depend on
A
The strength of the gravitational field at the location of the object
15
Q
What is the gravitational field strength of earth
A
9.8 N/Kg
16
Q
Weight is a ____ measured in ______
A
Force, newtons
17
Q
What do you use to measure weight
A
Calibrated spring balance
(Newtonmeter)
18
Q
Mass is ___ _ _____. It is measured in _________
A
Not a force, kilograms
19
Q
What do you use to measure mass
A
Mass balance
20
Q
How do you calculate weight
(N)
A
Mass × gravitational field strength
(Kg) (N/Kg)
21
Q
What is the gravitational field strength of the moon
A
1.6 N/Kg
22
Q
What does increasing the mass of an object do
A
Increases the weight
23
Q
What does doubling the mass of an object do
A
Doubles the weight
24
Q
Weight and mass are…
A
Directly proportional
W ∝ m
25
What does a free body diagram do
Shows all the forces acting on an object
26
What is a resultant force
Overall force on a point or object
27
What happens when a force moves an object through a distance
Energy is transferred and work is done on the object
28
Work done =
(J)
Force × Distance
(N) (m)
29
What can you draw to find resultant forces
Scale drawings (page 356 in CPG)
30
An object is in equilibrium if
All the forces acting on an object combine to give a resultant force of 0N
31
What can happen if you apply a force to an object
It could stretch, compress or bend.
To do this you need more than one force acting on the object
32
Work is done when a force stretches or compresses an object and causes energy to be transferred to the
Elastic potential energy store of the object
33
Elastic deformation
An object can go back to its original shape and length after the force had been removed
34
Objects that can be elastically deformed are called
Elastic objects e.g. a spring
35
Inelastic deformation
An object doesn't return to its original shape and length after the force has been removed
36
Extention is directly proportional to...
Force
F ∝ e
37
Force =
(N)
Spring constant × Extension
N/m (m)
38
A stiffer string has a...
Greater spring constant
39
Limit of proportionality
There is a limit to the amount of force you can apply to an object for the extension to keep increasing proportionally.
40
Limit of proportionality on a graph
There is a maximum force above which the graph curves showing that extension is no longer proportional to force.
41
Elastic potential energy =
(J)
½ × Spring constant × Extension²
(N/m) (m)
42
What is distance
How far an object has moved
43
What is displacement
The distance and direction in a straight line from an object's starting point to its finishing point e.g. a plane flew 5 metres north
44
What is speed
How fast you are going with no regard to the direction
45
What is velocity
Speed given in a direction
46
Distance travelled =
(m)
Speed × Time
(m/s) (s)
47
Speed of a person walking
1.5 m/s
48
Speed of a person running
3 m/s
49
Speed of a person cycling
6 m/s
50
Speed of a car
25 m/s
51
Speed of a train
55 m/s
52
Speed of a plane
250 m/s
53
What is acceleration
The change in velocity in a certain amount of time
(how quickly you are speeding up)
54
Acceleration =
(m/s²)
Change in velocity ÷ Time
(m/s) (s)
55
What is uniform acceleration
Means constant acceleration
56
Uniform acceleration equation
v² - u² = 2as
57
What does 'v' stand for
Final velocity
58
What does 'u' stand for
Initial velocity
59
Distance time graphs
What does the gradient represent
Speed - the steeper the graph, the faster the object is going
60
Distance time graphs
In flat sections the object is...
Stationary - it is stopped
61
Distance time graphs
Straight uphill sections mean...
It's travelling at a steady speed
62
Distance time graphs
Curves represent...
Acceleration or deceleration
63
Distance time graphs
A steepening curve means...
The object is speeding up (increasing gradient)
64
Distance time graphs
A levelling off curve means...
The object is slowing down (decreasing gradient)
65
Distance time graphs
If the object is changing speed you can find it's speed at a point by finding...
The gradient of the tangent to the curve at that point
66
Velocity time graphs
What does the gradient represent
Acceleration
67
Velocity time graphs
Flat sections represent...
Travelling at a steady speed
68
Velocity time graphs
The steeper the graph the greater the...
Acceleration or deceleration
69
Velocity time graphs
Uphill sections are...
Acceleration
70
Velocity time graphs
Downhill sections are...
Deceleration
71
Velocity time graphs
A curve means...
Changing acceleration
72
Velocity time graphs
The area under any section of the graph is...
The distance travelled in that time interval
73
What is friction
A force that always acts in the opposite direction to movement
74
How to reduce drag/air resistance
Keep the shape of the object streamlined - fluid can easily flow across it
75
Drag increases as...
Speed increases
76
Objects falling through fluids reach a...
Terminal velocity (steady speed)
77
Typically the less streamlined an object is...
The lower it's terminal velocity
78
Objects with large surface areas tend to have ______ terminal velocities
Lower
79
Newton's first law
A resultant force is needed to make something start moving, speed up or slow down
80
Newton's first law
The resultant force on a stationary object is 0 the object will...
Remain stationary
81
Newton's first law
If the resultant force on a moving object is 0 the object will...
Carry on moving at the same velocity (same speed and direction)
82
Newton's second law
Acceleration is directly proportional to...
Resultant force
83
Newton's second law
Acceleration is inversely proportional to...
Mass of the object
84
Newton's second law
Resultant force =
(N)
Mass × Acceleration
(Kg) (m/s²)
85
Inertia
Tendency for motion to remain unchanged
86
Newton's third law
When two objects interact the forces they exert on each other are equal and opposite
87
Newton's third law
If you push a shopping trolley it will...
Push back against you just as hard
88
Stopping distance is
Distance it takes to stop a car in an emergency
89
Stopping distance =
Thinking distance + braking distance
90
Thinking distance is
How far the car travels during the driver's reaction time (time between the driver seeing a hazard and applying the brakes)
91
Braking distance is
Distance taken to stop under the braking force (once the brakes are applied)
92
Thinking distance is affected by your speed...
Faster your going, further you'll travel during the time you take to react
93
Thinking distance is affected by your reaction time...
Longer your reaction time, longer your thinking distance
94
Factors that can affect reaction time for thinking distance...
Tiredness
Drugs
Alcohol
Distractions can affect ability to react
95
Braking distance is affected by your speed...
Faster a vehicle travels, longer it takes to stop
96
Braking distance is affected by the weather and road surface
If it's wet or icey or there is leaves or oil, there is less grip between the tyres and the road which can cause skidding
97
Braking distance is affected by the condition of tyres...
If tyres are bald (don't have any tread left) they can't get rid of water in wet conditions. Leads to skidding
98
Braking distance is affected by how good your breaks are...
If worn or faulty they can't supply as much force as well maintained brakes which can be dangerous when braking hard.
99
You can measure reaction time with the...
Ruler drop test
100
Typical person's reaction time is...
Between 0.2 and 0.9 seconds
101
Braking relies on friction between the...
Brakes and wheels
102
You can estimate the braking force required to make a vehicle decelerate and come to a stop by using the equations...
v² - u² = 2as and F = ma
103
Momentum =
(Kg m/s)
Mass × Velocity
(Kg) (m/s)
p = mv
104
Momentum is the...
Amount of 'oomph' an object has. All moving objects have it
105
The greater the mass of an object or the greater its velocity the...
More momentum the object has
106
Conservation of momentum is..
In a CLOSED system the total momentum before an event is the same as after the event
Physics
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