Forces & Motion Flashcards
(106 cards)
1
Q
How do you know which part of a journey shown on a distance/time graph has the highest speed?
A
steepest line
2
Q
What is average speed?
A
total distance / whole time of journey
3
Q
Name a scalar and vector measured in metres.
A
distance, displacement
4
Q
What is the SI unit for speed?
A
Meters per second (m/s)
5
Q
What does acceleration mean?
A
change in velocity in time
6
Q
What is the equation for calculating speed?
A
speed = distance / time
7
Q
How do we represent forces on diagrams?
A
arrows, with length depending on size of force
8
Q
In the acceleration equation, what does the ‘u’ stand for?
A
Initial velocity
9
Q
What does a horizontal line on a distance/time graph show?
A
stationary object
10
Q
What is the equation for calculating distance?
A
distance = speed x time
11
Q
Name a scalar and vector measured in m/s.
A
Speed, Velocity
12
Q
What are the units for acceleration?
A
metres per second squared
13
Q
How do you work out the gradient of a line on a graph?
A
vertical difference / horizontal difference
14
Q
What is the unit for speed if the time is measured in hours and the distance is measured in miles?
A
miles per hour
15
Q
How is a stationary object shown on a distance/time graph?
A
Horizontal line
16
Q
How fast is your walking speed?
A
typical pace = 3mph / 5 km/h / 1.4m/s
17
Q
In the acceleration equation, what does the ‘v’ stand for?
A
Final Velocity
18
Q
What is the speed of the sound of air?
A
approximately 330 m/s
19
Q
Is mass a vector or scalar?
A
Scalar
20
Q
Is energy a vector or scalar?
A
Scalar
21
Q
What is the maximum horizontal acceleration students are likely to experience in everyday in life?
A
about 1.5 m/s ² average family car
22
Q
What is force?
A
Push or pull
23
Q
What is the unit for mass?
A
Kilograms (Kg)
24
Q
Why is acceleration a vector?
A
it is measuring a change in another vector
25
How can speed be calculated?
From a distance and time
26
How can you calculate velocity from a distance/time graph?
gradient of line
27
What is the acceleration due to gravity?
10m/s ² to 1 S.F. / 9.8m/s ² to 2 S.F.
28
Runner A finishes a race in less time than Runner B. Who is faster?
Runner A
29
What does a vector have that scalar does not?
Direction
30
What does a vector have that a scalar does not?
direction
31
What is the difference between speed and velocity?
Velocity has a direction / is a vector
32
What is the equation for calculating acceleration?
change in velocity (v-u) / time
33
What two measurements are needed to calculate speed?
Distance and Time
34
How is a comstant speed shown on a distance/time graph?
straight, sloping line
35
What is the unit for speed used on the roads in the UK?
Miles per hour (mph)
36
What is the maximum legal speed for vehicles on UK roads?
70 mph / 31m/s
37
What is the equation for calculating acceleration from velocity and time?
Acceleration = change in velocity (v-u) / time
38
How does the mass of a moving object affect its acceleration?
higher mass, lower concentration
39
Two forces on an object are in opposite directions. How do we calculate the resultant force?
Find the difference between them
40
What is the name for the force of the object that acts in the same way as all the other forces combined?
resultant
41
For the same force, how does reducing the mass of an object affect its acceleration?
increases it
42
How can friction act to make a car slow down?
in brakes
43
How does the velocity affect momentum?
higher velocity, higher momentum
44
What does ‘thinking distance’ mean?
the distance a car travels while the driver is reacting to a danger and deciding to apply the brakes
45
How does the force needed for an acceleration depend on the size of the acceleration?
larger acceleration, larger force needed
46
What word describes both the speed and direction of a movement of an object?
velocity
47
What does ‘momentum is conserved’ mean?
Total momentum is the same before and after a collision
48
How does the mass affect momentum?
higher mass, higher momentum
49
When will a resultant force act to slow down a car?
When backward forces are greater than forward ones
50
What factors affect the momentum of a moving object?
mass, velocity
51
An object has a negative acceleration. What does this mean?
It is slowing down
52
An aeroplane has thrust of 2000 N and a drag of 1800 N. What is the resultant?
200 N forwards to
53
What provides the centripetal force for a car going around a roundabout?
Friction
54
For the same mass, how does increasing the mass affect the acceleration?
Increases it
55
Name two quantities that are vector.
force, velocity, acceleration, displacement, weight, momentum
56
What are the forces on the moon orbiting around a planet?
Gravity acting towards the planet
57
What does ‘braking distance’ mean?
The distance a car travels while slowing down
58
What is the force that pulls us towards the Earth?
Gravity
59
Give two examples of scalar quantities.
Speed, mass, distance, energy
60
What happens when there is a result force in the opposite direction to the movement of an object?
It will decelerate / slow down
61
I’m which direction does centripetal force act?
Towards the centre of the circle
62
How does speed affect the braking distance
Higher speed, longer braking distance / braking distance directly proportional to speed squared
63
What force stops your foot slipping on the ground when you walk?
Friction
64
Name a vector quantity that changes as as a car drives at a constant speed around a roundabout.
Velocity
65
What is the name of the force that makes objects move in a circular path?
Centripetal force
66
Two forces on an object are in the same direction. How do we calculate the resultant force?
Add
67
What is the direction of the resultant force on a bycicle that is slowing down?
Backwards
68
How can the pilot of an aeroplane make the plane gain speed upwards?
Increase the lift / upwards force
69
An object is moving at a constant velocity. What can you say about the forces on it?
Balanced
70
What is the direction of the resultant force on a car speeding up?
Forwards
71
What factors affect the momentum of a moving object?
Mass, velocity / speed
72
What are balanced forces?
Forces of the same size in opposite directions
73
How will being tired feet reaction time?
Slow it down
74
How will being tired affect reaction time?
Make it longer
75
How do balanced forward affect the velocity of a moving car?
The car continues with the same velocity
76
What is the name for a single force on an object with the same affect as all the forces combined?
Resultant
77
What is the name for a single force on an object with the same effect as all the forces combined?
Resultant
78
What effect does drinking alcohol have on human reaction times?
slows them down/makes them longer
79
Why is the force of gravity greater on a lorry than on a car?
Larger mass
80
How does a sideways resultant force affect the velocity of a moving object?
Changes its direction
81
Name two vector quantities connected with movement.
Velocity, acceleration, displacement, momentum
82
What are the units for force
Newtons (N)
83
You pedal faster on a bycicle. What happens?
You accelerate / get faster
84
Air resistance on a cyclist is 20 N and friction is 5 N. What is the total force trying to slow the cyclist down?
25 N backwards
85
Name one force that actually had to be taken into account when working out the resultant force on a moving object?
Drag or friction
86
What is inertial mass?
Mass obtained from a force and acceleration / a measure of how difficult it is to change the velocity of an object
87
What does the length of a force arrow on a diagram represent?
Size of force
88
What does the length of a force arrow on a diagram represent?
Size of force
89
What is the equation relating acceleration, force and mass?
F = m x a
90
How does the force applied to an object affect its acceleration?
Larger force, larger acceleration
91
What is ‘drag’ another name for?
Air resistance or water resistance
92
What is the SI unit for time?
Seconds (s)
93
What does ‘conservation’ mean in phrases such as ‘conservation of energy’?
Total amount stays the same
94
How does speed affect the thinking distance?
Higher speed, longer thinking distance / thinking distance directionally proportional to speed
95
What are unbalanced forces?
Forces of different sizes in opposite directions
96
What type of force is used to slow down a moving vehicle?
Friction
97
What do we call the forwards force produced by an aeroplane’s engine or propeller?
Thrust
98
Name the two factors that affect the acceleration of an object.
Force and mass
99
What do you feel if you stretch a spring more and more?
Spring pulls back more and more
100
How can friction act to make a car speed up?
Between tyres and roads
101
How are the values for a mass and the inertial mass of an object different?
They aren’t
102
Name a force that accelerates objects downwards?
gravity / weight
103
Why is a wet road mlre slippery than a dry one?
Water acts as a lubricant
104
What are the usual units for velocity in physics?
meters per second (m/s)
105
Why is the resultant force accelerating a car usually less than the force provided by its engine?
Air resistance and / or friction
106
How do we describe the forces on an object when the force in one direction is bigger than the force in the other direction?
Unbalanced
