Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Physics > Topic 5 Forces > Flashcards

Topic 5 Forces Flashcards

1
Q

Force is ——– quantity

A

vector quantities have a magnitude and a direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Some physical quantities have only ———- and no ————–
these are called ——————– quantities

A

magnitude and no direction
scalar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Examples of vector quantities:

A

force,velocity,displacement,acceleration,momentum etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Examples of scalar quantities:

A

speed,distance,mass,temp,time etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Vectors are usually represented by an arrow the length of the arrow shows the———and the direction of the arrow shows the ————-

A

magnitude
direction of the quantity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

A force is

A

a push or pull on an object that is caused by it interacting with something

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

give an example of a contact force

A

friction, air resistance, tension in ropes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

give an example of a non contact force

A

magnetism. gravitational force , electrostatic force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

An interaction pair is a

A

pair of forces that are equal and opposite and act on two interacting objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

mass is just the amount of ———- for any given object this will have the —— value ———

A

‘stuff’ in an object.
same
anywhere in the universe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Weight is the ——

A

force acting on an object due to gravity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Gravitational field strength varies with location and its ——- the closer you are to the mass causing the field and stronger for larger——–

A

stronger
masses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

weight is measured using a

A

newton-meter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Mass is not a ———-
and is measured in ———

A

force
kilograms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do calculate an object’s weight if you can’t measure it equation

A

weight (N)= Mass (kg) * Gravitional Field Strength (N/kg)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the forces acting on a skydiver and what these do

A

weight acts on him pulling him towards the ground and drag (air resistance) also acts on him, in the opposite direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Step by step of how you work out resultant forces using scale diagrams:

A

1.Draw all forces on an object to scale ‘tip-to tail’
2. Then draw a straight line from the start of the first force to the end of the last force-this is the resultant force (in a triangle)
3. Measure the length of the resultant force on the diagram to find the magnitude and the angle to find the direction of the force (the bearing)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

If all forces acting on an object combine to give a resultant force of 0, the object is in———
On a scale diagram this means that the —- of the last force you draw should end where the —- of the first force you drew begins.
E.g. for three forces, the scale diagram will form a——–

A

equilibrium.
tip
tail
triangle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

You can spilt a force into components because not all forces act ———- or ———– some exact as ——– angles
To make these easier to deal with they can be split into ————————————————
You can resolve a force (split it into components) by drawing it on a -scale grid-

A

horizontally vertically
awkward

two components at right angles to each other (usually horizontally or vertically)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

when an object stretches compresses or bends you need ———————- force otherwise the object would simply ——- in the direction of the ———– instead of ———————

A

more than one
move
applied force
changing shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

An object has been elastically deformed if it can go back to its’s …….:

A

original shape and length after the force has been removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

If an object has been in-elastically deformed if it :

A

doesn’t return to it’s original shape and length after the force has been removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

elastic objects are only elastic ———

A

up to a certain point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The extension of a stretched spring isdirectly proportional to

So the equation is

This equation also works for com—–where e is

A

directly proportional to the load or force applied

Force (N)= Ke
Spring Constant (N/m) * Extension (m)

compression
just the difference between the natural and compressed lengths- the compression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
the spring constant k, depends on the material that you are stretching- a stiff spring has a ------------ spring constant
greater
26
There is a limit to the amount of ------- you can apply to an object for the ---------- to keep on increasing -------- this is known as the limit of ---------
force extension proportionally proportionality
27
extension is not just the ------ of the spring its the----------between the stretched length and the ----------- un-stretched length
length difference original
28
As long as a spring is not ----------- past its limit of -------------- work done in stretching or compressing a spring can be found using:
stretched proportionality E (J)= 1/2Kesquared Spring constant (N/m) and extension in (m)
29
a moment is the
turning effect of a force
30
moment equation what is the distance measuring?
moment (Nm)= Force (N)*Distance (m) The perpendicular distance from the pivot to the line of action of the force
31
if the total anticlockwise moment equals the total clockwise moment the object is :
balanced and won't turn
32
Levers increase the -------- from the pivot at which the ---------- is applied and since moment = force*distance this means that less ------- is needed to get the ------- moment
distance force same moment
33
Gears are- circular discs with teeth around their edges Their '-------' -------- so that turning causes ---------- to turn in the --------------------
circular discs 'teeth' around their edges teeth interlock another opposite direction
34
Why are different size gears used? A force transmitted to a larger gear will cause a --------- because ..... The larger gear will turn -------- than the smaller gear
to change the moment of a force bigger moment the distance to the pivot is greater slower
35
Pressure is force per --------------
unit area
36
Density is a measure of the '----------' of a substance how -------- together the particles in a ----------- are For a given liquid the density is -------- The density of a gas can --------- though
compactness close substance uniform vary
37
The more dense a given liquid is the more -----it has in a certain space. This means this means there are more particles able to ---------- so -------- is higher
particles collide pressure
38
As the depth increases the number of particles ------ that point ---------. The ------- of these particles adds to the -------- felt at that point . So liquid --------- increases with depth.
above increases weight pressure pressure
39
upthrust determines whether an object will ---- or ------
sink , float
40
when an object is submerged in a fluid (either partially or completely) the-------- of the fluid exerts a -------on it from ------------- -----------increases with depth so the force exerted on the bottom of the object is --------than the force acting on top of the of the object This causes a ------- force upwards known as -------- The upthrust is equal to the weight of the ------ that has been -------- by the object.
pressure force every direction Pressure larger resultant upthrust fluid displaced
41
If the upthrust on an object is equal to the objects weight then: If an objects weight is more than the upthrust : This means that whether or not an object will ------- depends on its ------------
the forces balance and the object floats it sinks float density
42
How do submarines make use of upthrust?
To sink large tanks are filled with water to increase the weight of the submarines so that it is more than the upthrust . To rise to the surface, the tanks are filled with compressed air to reduce the weight so that its less than the upthrust
43
Atmospheric pressure is : It's acting on you at.... and varies with your height ... it is created on a surface by: The atmosphere is a layer of ------ that surrounds the ------
the pressure exerted by the air around you. all times above sea-level air molecules colliding with the surface air , earth
44
atmospheric pressure ---------- with height This is because:
decreases as the altitude increases the atmosphere gets less dense so there a fewer air molecules that are able to collide with the surface. There are also fewer air molecules above a surface as the height increase. This means that the weight of the air above it, which contributes to atmospheric pressure, decreases with altitude
45
Why do mountain climbers carry gas tanks:
lower density of air higher up so less air particles so less oxygen
46
Distance is a ---------- quantity because it doesn't involve --------- Displacement is a ---------- quantity
scalar direction vector
47
speed an velocity both measure how fast you are going but speed is --------- and velocity is a --------
scalar vector
48
average speeds for: a person walking speed a person running speed a person cycling speed a car speed a train speed a plane speed
1.5 m/s 3 m/s 6 m/s 25 m/s 55 m/s 250 m/s
49
the speed of sound at ------ in air changes depending on what the sound waves are travelling through
330 m/s
50
wind speed can be affected by things like;
temp, large buildings an atmospheric pressure
51
acceleration is
the rate of change of velocity
52
uniform acceleration means a -------- acceleration due to gravity is ------- for objects in free fall . It's roughly ------- near the earth's surface and has the same value as ------------------------
constant acceleration free fall 9.8 m/s squared gravitational field strength
53
If an object has no force propelling it along it will always ------------------ and ---------- due to -----------(unless you're in space an theres nothing to rub against) ---------- always acts in the -------- direction to movement
slow down and stop friction friction opposite
54
To travel at a ------- speed the driving force needs to ------------ the frictional forces You get friction between two surfaces in --------- or when a object passes through a ---------- this is called --------- air resistance is a type of --------- The most important by far in reducing --------- is keeping the object ----------. This is where the object is -------- to allow fluid to --------- it reducing ---------- parachutes work in the -------- way they want as much ------- as possible
steady balance contact fluid drag drag drag streamlined easily flow across drag opposite drag
55
drag increases as ------ increasess
speed
56
when talking about resistive forces in exam when object travelling through air say 'air ----------' and not drag
resistance
57
If an object falls for long enough it will reach its ------------- velocity / maximum ---------
terminal speed
58
How do objects falling through a fluid reach a terminal velocity:
1.when falling objects first set off the force of gravity is much more than the frictional force slowing them down so they accelerate 2. as the speed increases the friction builds up 3.This gradually reduces the acceleration until eventually the frictional force is equal to the accelerating force ( so the resultant force is zero) 4. It will have reached its maximum speed or terminal velocity and will fall at a steady speed
59
terminal velocity depends on ------ and -------- The accelerating force acting on all falling objects is ------------and it would make them all fall at the same -------, if it wasn't for --------
shape area gravity rate air resistance
60
Newton's first law say's that
if the resultant force on a stationary object is 0 the object will remain stationary. If the resultant force on a moving object is 0it'll just carry on moving at the same velocity (same speed and direction)
61
an non 0 resultant force will always produce acceleration or deceleration in the ---------- of the force
direction
62
newtons second law :
that F (N)= m(kg)a (m/s squared), or resultant force is equal to mass times acceleration. A larger resultant force acting on an object causes a larger acceleration, and objects with larger mass require more force to accelerate.
63
Inertia is the -------- for motion to remain unchanged. Until acted on by a----- objects at rest ----- at rest and objects --------- stay at a steady speed will stay moving at that ----- this tendency to continue in the same state of ----- is called ------- An objects' inertia mass measures: Inertia mass can be found using:
tendency force moving speed motion inertia how difficult it is to change the velocity of an object Newtons second of law of motion f=ma rearranging this to m=f/a so inertia mass is just the ratio of force over acceleration
64
Newtons third law says that: If you push something say a shopping trolley , the trolley will push back against you just as ------and as soon as you stop pushing so does the ------ The slightly tricking thing to get your head around is that if the forces are always----how does anything go anywhere? The important thing to remember is that the two forces are acting on --------- objects
when two objects interact the forces they exert on each other are equal and opposite hard trolley equal different
65
Stopping distance=
thinking distance + braking distance
66
the thinking distance :
how far the car travels during the driver's reaction time
67
The braking distance:
the distance taken to stop under braking force
68
thinking distance is affected by:
your speed- the faster your going the further you'll travel during the time you take to react your reaction time- the longer your reaction time the longer your thinking distance this can be affected by tiredness drugs, or alcohol. distractions like kids in car can also affect your ability to react
69
Braking distance is affected by :
your speed- for a given braking force, the faster a vehicle travels, the longer it takes to stop The weather or road surface - if it is wet or icy or there are leaves or oil on the road there is less grip ( less friction) between a vehicles tyres and the road which can cause tyres to skid The condition of the tyres- if the tyres are bald- (they don't have any thread left) then they cannot get rid of water in wet conditions . This leads to them skidding on top of the water. How good your brakes are- if brakes are worn or faulty they won't be able to apply as much force as well maintained brakes, which could be dangerous when you need to brake hard.
70
the longer your stopping distance the more -------- you need to leave ------ of a car to stop ---------
space in front safely
71
A typical reaction time is between ---- and ---- seconds
0.2 and 0.9
72
braking relies on -------between the -------- and --------- when the brake pedal is pushed this causes: This ------- causes -------- which causes --------- The ------------ between the brakes and the wheels transfers energy from the ---------- stores in the wheels to the --------------- of the brakes . The brakes increases in ----------. The faster a vehicle is going the more energy it has in it -------- store , so the more ------ needs to be done to ------- it . This means that a greater ------ force is needed to make it ------ within a ---------------- A larger braking force means a ------------- deceleration . very large decelerations can be --------because they may cause :
friction brakes pedals brake pads to be pressed onto the wheels . contact friction work to be done work done kinetic energy stores thermal energy stores temp kinetic energy work stop braking stop certain distance large dangerous brakes to overheat (so they don't work as well) or could cause the vehicle to skid
73
speeds affects braking distance more than ------- distance
thinking
74
In a closed system which is just a fancy way of saying: The total momentum before an event (eg.colision) is the ----- after an event. This is called:
that no external forces act on something same conservation of momentum
75
If the momentum before an event is 0 then the momentum after will be -------- After an explosion pieces fly off in different directions so that -------- cancels out to ------
0 total momentum 0
76
when a force acts on an object it causes it to ------------------ The bigger the force the ------------- the change in momentum
change momentum faster
77
Cars have many safety features such as and what they do:
crumple zones: which crumple on impact, increasing the time taken for the car to stop seat belts: which stretch tightly increasing time taken for the wearer to stop Air bags inflate before you hit the dashboard of a car . the compressing air inside it slows you down more gradually than if you has just hit the hard dashboard.
77
What about bike helmets why are they safe?
contain a crushable layer of foam which helps to lengthen time taken for your had to stop in a crash reducing impact on brain
77
Conservation of momentum explains why a gun or cannon recoils backwardswhy :
when it is fired. When a cannon is fired, the cannon ball gains forward momentum and the cannon gains backward momentum. Before the cannon is fired (the`` ‘event’), the total momentum is zero. This is because neither objectThe total momentum of the cannon and the cannon ball after being fired is also zero, with the cannon and cannon ball moving in opposite directions.
78
crash mats and cushioned playground flooring increase the time taken for you to stop if you fall on them. this is because they are made from :
soft compressible (squish-able) materials
79
Explain why a car has a maximum speed (6 marker)
there is a maximum forward force as the speed of the car increases air resistance increases until air resistance is equal in size to forward force so the car can no longer accelerate
80
To get a maximum moment you need to push at: any other angle will produce a smaller moment
right angles
81
as far as I know there is no velocty time graphs and distance time graphs aswell as no required pracs here

Physics (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions