Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

A SL Physics 2024/2025 > A.2 Forces and Momentum > Flashcards

A.2 Forces and Momentum Flashcards

(87 cards)

Start Studying
1
Q

Resultant force

A

Sum of all the forces acting on an object

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

Resolving forces

A

A single force can be resolved (broken down) into two components at 90* to each other

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

Newton’s first law

A

An object continues in uniform motion in a straight line or at rest unless a resultant external forces acts

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

Newton’s second law

A

The resultant force on an object is proportional to the acceleration providing the mass of the object remains constant

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

Newton’s third law

A

For every action on an object there is an equal but opposite reaction on another object

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

Two types of forces

A

Contact and field

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

Contact forces

A

Requires objects to be in contact with each other

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

Contact forces example

A

Normal, friction, tension, elastic

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

Field forces example

A

Gravitational, electric, magnetic

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

Field force

A

Force that can act at a distance

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

Normal force

A

When an object pushes on a surface, surface pushes back on the object

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

Objects on an incline - normal force is calculated how?

A

Fn = mg + Fn=mgcos0 on an incline

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

Components of the weight force are split up how in an object on the incline

A

Going down the slope is mgsin0, acting on an angle is mgcos0, weight is mg

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

Surface friction

A

Force that opposes motion on two solid objects

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

Static friction

A

When a force is applied to an object but the force is not large enough to move the object, static friction acts

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

What happens when static friction reaches a maximum value?

A

It becomes dynamic friction and the object starts moving

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

What is the magnitude of static friction equal to?

A

The magnitude of the applied force

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

What is the coefficient of friction value?

A

Ratio of two forces (Ff and Fn)

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

How to calculate coefficient of static friction?

A

tan0, when the block is about to move

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

What happens when the force applied to the object exceeds the maximum static friction force?

A

It becomes dynamic friction and the object is moving

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

Which is bigger, static or dynamic friction?

A

Static friction

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

What is the maximum value for a coefficient of friction?

A

Usually 1.0

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

Viscous drag force

A

The force acting on a moving object due to the viscosity of the fluid which it is moving through

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

What does the size of the drag force depend on? (6 factors)

A

Shape, size, surface and cross section of object, viscosity of fluid, speed of object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Why can't Stoke's law be used on big objects?
Turbulent flow (laminar) occurs
26
What does an object need to be to calculate drag force?
A small smooth sphere
27
Buoyancy
Ability of a fluid to provide a vertical upward force on an object placed on or in it
28
What is the size of the buoyancy force equal to?
The weight of the fluid displaced
29
An object will sink until when
When it has displaced its own weight of fluid
30
If an object is floating, which two forces are balanced
Weight force and buoyancy force
31
When an object is falling through a fluid, three vertical forces act on it - which three
Weight down Buoyancy upwards Viscous drag upward
32
What are the two constant forces on an object falling through a fluid?
Weight force downward, buoyancy upwards
33
What is the changing force on an object falling through a fluid?
The viscous drag force will increase as the speed increases
34
What are the forces on an object falling through a fluid at terminal velocity?
Fb+Fd = Fg
35
Tension force
A pulling force, may cause on object to stretch
36
Magnitude of the restoring force is equal to what?
The extension of length
37
Elastic restoring force (Fh)
The object will exert a restoring force to return the object to the equilibrium position
38
Spring constant
K, value that represents the stiffness of the object. Larger the force, stiffer the object. (Nm-1)
39
What direction does a restoring force act in?
Opposite direction to the extension
40
Object behaving elastically
Returns to original position after being stretched
41
Maximum extension
After it is stretched past this point, it will be permanently deformed. Elastic limit
42
Force fields
Region of space where an object may experience a force due to a property such as mass or charge
43
Gravitational force field
A region of space where an object experiences a force due to its mass
44
g
Gravitational field strength, 9.8Nkg-1 at earth's surface
45
What can gravitational force also be referred to when on earth?
Weight force
46
Free body diagram
A diagram that shows all the forces acting on an object
47
Balanced forces
Object remains at rest or continues at constant speed in a straight line
48
Unbalanced forces
Forces in opposite direction are unbalanced, accelerates in direction of greater force
49
How heavy we feel depends on what force?
Normal force
50
If an object is in equilibrium, the sum of all forces...
Will add to 0 so resultant forces are 0
51
p
Linear momentum, Ns
52
Linear momentum (p)
The product of mass and velocity of an object. It is a vector so has both magnitude and direction (Ns)
53
What happens when an impulse is applied to an object with constant linear momentum?
The change in p will be equal to the impulse.
54
j
Impulse, Ns
55
Why can't Newton's 2nd law be used sometimes?
It assumes mass is constant, if mass is changing use change in p/change in t
56
How may an impulse be found without a formula?
Area under a force time graph
57
Law of conservation of momentum
The total linear momentum of a system remains constant provided no resultant external force acts on the system
58
What does the law of conservation of momentum allow us to determine?
The outcome of collisions and explosions
59
What happens to total energy in collisions?
It is conserved
60
Elastic collision
No kinetic energy is lost (occurs between subatomic particles)
61
Inelastic collision
Kinetic energy is lost (converted to heat and sound)
62
What happens to kinetic energy in an explosion and why?
It increases and comes from the energy source of the explosion ie chem pot or elastic pot
63
What is angular velocity?
Angular displacement (angle) over time taken
64
Angular velocity units and symbol
Symbol w, units rads-1
65
Centripetal acceleration
Acceleration towards the centre of a circle
66
Centripetal force
Unbalanced force that acts to create circular motion
67
How to break down a resolving force?
Vertical is Fsin0 and horizontal is Fcos0
68
Translational equilibrium
When a resultant force on an object is zero and it is not accelerating
69
What is the magnitude of static friction equal to?
Magnitude of the applied force
70
Density
Mass/volume
71
Angular velocity formula
2 π f
72
How can an object be moving at a constant speed in a circle but still be accelerating?
Acceleration is rate of change of velocity, direction of motion is constantly moving so velocity is constantly changing.
73
Centripetal force formulas x2
F=mv^2/r and F=mw^2r
74
What are the balances of the forces in horizontal circular motion?
Vertical forces are balanced, there is an unbalanced horizontal force to the centre of the circle
75
Where does centripetal force come from in horizontal circular motion?
Friction between tyres and road
76
Horizontal circular motion - what happens if the car travels at a speed where the friction force is not large enough to provide a centripetal force?
Car continues in a straight line at a tangent to the bend
77
Where does centripetal force come from in banked corners?
The horizontal component of the normal force
78
What forces can the normal force be resolved into on banked corners?
Vertical component - balances weight, horizontal component - provides centripetal force
79
Two key differences between vertical and horizontal motion
- Vertical motion speed is not constant - Vertical motion - size of normal force varies throughout the motion
80
Forces acting at the top of a loop (vertical circular motion)
Fg+Fn=Fc
81
Formula for minimum speed
v= √rg
82
What would you feel if normal force was 0?
Weightless sensation
83
Forces acting on the bottom of a loop (vertical circular motion)
Fn up, Fg down. Fc=Fn-Fg
84
Kinetic energy in a vertical circular motion loop
Ek (bottom) must = Ek(top)+Ep(top)
85
DELETE
DELETE
86
Viscosity
Resistance of a fluid to movement through it (n, Pas)
87
Density symbol and unit
p, kgm^-3

A SL Physics 2024/2025 (20 decks)

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