Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Eleanor Rowe Physics > Forces > Flashcards

Forces Flashcards

1
Q

What is a vector quantity with examples

A

Has magnitude and direction

Eg force velocity displacement acceleration momentum

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

What is a scalar quantity with eg

A

Only magnitude no direction

Eg speed distance mass temperature time

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

How are vectors shown

A

As an arrow

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

What is a contact force with eg

A

When two objects have to touch for a force to act

Eg friction air resistance tension in rope normal contact force

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

What is a non contact force with eg

A

Objects don’t need to be touching for the force to act

Eg magnetic force gravitational force electrostatic force

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

How are the sun and earth attracted to each other

A

Gravitational non contact force

Equal but opposite attraction is felt

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

What is gravity

A

The force of attraction between masses

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

What are the two important effects of gravity

A

Makes everything fall towards the ground on the surface of the earth
Gives everything a weight

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

What is mass
What is it measured in
What is it’s symbol

A

The amount of matter in an object
Kg
m

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

What is weight
What is it measured in
What is it’s symbol

A

The force acting on an object due to gravity
Newton’s (N)
W

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

Is mass a force

A

No

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

True/false: mass and weight are directly proportional

A

True

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

What is the equation including gravity mass and weight

Include symbols and units

A

Weight (W) (Newton’s) = Mass (m) (Kg) x Gravitational Field strength (g) (N/kg)

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

What two forces act on a skydiver

A

Drag (air resistance) and weight

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

What is a free body diagram?

A

Diagram showing all the different forces acting on one isolated system
Length of arrows shows scale of how large each force it

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

What is a resultant force

A

The overall force on a force or object

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

Finish the sentence: when a force moves an object through a distance…

A

Energy is transferred and work is done on the object

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

What is the equation linking force work and distance with symbols and units

A

Work done (W) (J) = Force (F) (Newton’s) x Distance (s) (m)

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

What is one joule of work equal to

A

When a force of one newton causes an object to move one meter
1J=1Nm

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

What is elastically deformation

A

What an object can’t go back to its 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
21
Q

What is inelastically deformation

A

The object doesn’t return to its 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

What happens when work is don’t to compress a spring

What happens if the object is inelastically deformed

A

Energy is transferred to the elastic potential energy store of the object
All the energy is in elastically deformation
Only some is in inelastically deformation

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

What is the equation that links spring constant force and extension with symbols and units

A

Force (F) Newton) = spring constant (k) (N/m) x Extension (e) (m)

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

Does a stiffer spring have a greater or lower spring constant

A

Greater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How is the limit for the amount of force applied to extend a spring shown on a graph and what is this called
The graph starts to curve showing force and extension are no longer proportional Called the limit of proportionality
26
Practical method for investigating link between force and extension
Measure natural length of spring ( read at eye level) Add mass to spring, record new length of spring Repeat process until enough measurements Plot a graph Will only start to curve if exceed limit of proportionality
27
What is the equation for elastic potential energy with units and symbols
Elastic potential energy (E) (J) = 0.5 x spring constant (k) (N/m) x extension^2 (e) (m)
28
What is a moment
The turning effect of a force
29
What is the equation for moments with symbols and units
Moment (M) (Nm) = Force (F) (N) x distance (m)
30
What is the distance in the moment equation
The perpendicular distance from the pivot to the line of action of the force
31
How do levers make it easier to do work
They increase the distance from the pivot meaning less force is needed to get the same moment
32
What are gears
Circular disks with teeth around the edges
33
How do gears work
Their teeth interlock so that turning one causes another to turn in the opposite direction Used to transmit the rotational effect of a force from one place to another
34
True or false a smaller gear will turn slower than a large gear
False a large gear turns slower
35
How will a force transmitted to a larger gear cause a bigger moment
The distance to the pivot is bigger
36
How do you calculate the pressure at the surface of a fluid | Equation with symbols and units
Pressure (p) (Pa- pascals) = Force Normal to a surface (N) / Area of that surface (m^2)
37
How does fluid exert a pressure
The particles exert a force on the object they collide with
38
What does pressure in a liquid depend on
Density - more dense it is , more particles in a certain space, more collisions = higher pressure Depth- number of particles above that point increases, weight of this adds to pressure felt at that point = higher pressure
39
How do you calculate pressure at a certain depth due to the column on liquid above Equation with symbols and units
Pressure (p) (Pa) = Height of Columbia of liquid (m) x gravitational field strength (N/kg) x density of liquid (kg/m^3)
40
How is upthrust formed when an object is in fluid
Pressure increases with depth, so there is more pressure at the bottom of the object than at the top, this causes a resultant force called upthrust
41
What is upthrust equal to when an object is in fluid
The upthrust is equal to the weight of the fluid that has been displaced by the object
42
What happens is the fluid an object is placed in is denser than the object
The fluid it displaces equals in weight to the object so it floats
43
What happens is the object is denser than the fluid it is placed in
It is unable to displace enough water to equal its weight | Meaning weight is larger than upthrust so it sinks
44
How do submarines use upthrust to work
To sink large tanks are filled with water to increase its weight to be more than the upthrust To ride the tanks are filled with air to reduce the weight so it is less than the upthrust
45
How is atmospheric pressure created at the surface
By air molecules colliding with the surface
46
How does atmospheric pressure decrease with increased altitude
The atmosphere gets less dense to there are fewer air molecules that are able to collide with the surface There are also fewer air molecules above a surface as the height increases so pressure is reduced
47
What is displacement
Measures the distance and direction in a straight line from a starting point to ending point
48
What is the equation for time speed and distance with symbols and units
Distance (s) (m) = speed (v) (m/s)x time (t) (s)
49
What are the typical speeds for walking running cycling a car a train and a plane
``` Walking 1.5m/s Running 3m/s Cycling 6m/s Car 25m/s Train 55m/s Plans 250m/s ```
50
What is acceleration
How quickly you’re speeding up
51
What is the equation for acceleration with symbols and units
Acceleration (a) (m/s^2) = change in velocity (m/s) / time (s)
52
What is another name for uniform acceleration
Constant acceleration
53
What is acceleration due to gravity as a value
9.8 m/s^2
54
What is the equation for uniform acceleration and what does each part mean
v^2 - u^2 = 2 x a x s ``` v= final velocity u = initial velocity a= acceleration s = distance ```
55
On a distance time graph what does the gradient equal
The speed
56
What do flat sections mean in a distance time graph
The object is stationary
57
What do curves mean in a distance time graph
Acceleration or deceleration
58
What does the gradient mean in a velocity time graph
The acceleration
59
What do flat sections mean in velocity time graphs
Steady speed
60
What do curves mean in velocity time graphs
Changing acceleration
61
What does the area under and velocity time graph mean
The distance travelled
62
What is friction
A force that always acts in the opposite direction to movement
63
What is friction called through a fluid
Drag
64
What happens to drag when speed increases | How can this be stopped
It increases | Keep the object streamlined allowing fluid to flow easily across it
65
How do parachutes use drag
They increase their SA to make it difficult for fluid to flow across it, slowing them down
66
How does an object falling through fluid reach a terminal velocity
When it first sets off, the force of gravity is much more than the frictional force slowing it down so it accelerates As speed increases, friction builds up This gradually reduces acceleration until the frictional force is equal to the accelerating force At this point there is no resultant force and the object has reached its max speed or terminal velocity
67
What does terminal velocity depend on
Shape and area
68
What is a good example for showing that shape and area effect terminal velocity
A human skydiver with no parachute will have less air resistance meaning their terminal velocity is dangerously higher A human skydiver with a parachute will have more air resistance meaning their terminal velocity is at a lower safer rate
69
What is Newton’s first law
A resultant force is needed to make something start moving speed up or slow down
70
What is Newton’s second law
Acceleration is proportional to the resultant force
71
What formula shows Newton’s second law with symbols and units
Resultant Force (F) = mass (m) (kg) x acceleration (a) (m/s^2)
72
What is inertia
The tendency for motion to remain unchanged
73
Will something with a higher or lower mass have a greater inertia
Higher
74
What is Newton’s third law
When two objects interact, the forces the exert on each other are equal and opposite
75
Method for practical to investigate how mass and force affect acceleration
Set up trolly holding card with gap in middle to interior light gate twice ( will calculate velocity) Connect trolly to string through pulley and add hook on end to hang mass on Masses added provide accelerating force Mark starting line so trolley always travels same distance Release trolley and record acceleration Repeat by adding masses
76
What is the equation for stopping distance
Thinking distance + braking distance
77
What factors affect stopping distance
Speed, reaction time, weather, brake and tire condition
78
How do car brakes work
``` Brake pads press onto wheels Causes friction Causes work to be done Transfers energy from kinetic stores in wheels to thermal stores in brakes Causes increase in temperature ```
79
How to measure reaction times
Ruler drop test
80
How does speed affect braking distance
As speed doubles, kinetic energy increases 4 fouls (2^2), so the braking distance also increases 4 fold
81
What is the equation for momentum with symbols and units
Momentum (p) (kg m/s) = mass (kg) x velocity (m/s)
82
What happens to momentum in a closed system
Momentum before event is the same as after the event
83
What does a larger farce mean in terms of change in momentum
A faster change in momentum
84
How is a fast change in momentum dangerous in a car crash
The forces on the body will be very large and more likely to cause injury
85
Why do cars have safety features
Designed to slow people down over a longer time when they have a crash The longer it takes for a change in momentum the smaller the force felt, meaning injuries are less severe
86
What safety features do cars have and what do they do
Crumple zones increase time taken for car to stop Seat belts stretch slightly increase time sod wearer to stop Air bags inflate and compressed air slows you down more gradually than hitting head on dashboard

Eleanor Rowe Physics (11 decks)

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