Brainscape's Knowledge GenomeTM

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


See full index

physics > Forces > Flashcards

Forces Flashcards

1
Q

What is a scalar and vector quantity?

A

A scalar only has magnitude

A vector has magnitude and direction. Force is a vector quantity

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

What is a contact force and give examples?

A

objects are actually touching. E.G friction,tension,air resistence,upthrust

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

What is a non contact force and give examples?

A

Objects are not touching. E.G gravitonal force,electrostatic force ,magnetic force

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

What is gravity?

A

force of attraction between all mases
Mass is the amount of matter it contains and is constant
Weight is the force acting on an object due to gravity
Weight= mass x gravitational field strength (W=mg)

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

What is resultant force?

A

More then one force is acting on an object and they can be replaced with a single force which has the same effect
Force = Mass x Acceleration
F=ma

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

How is work done?

A

when a force causes an object to move ,work is done on the object
when work is done, energy transfers takes place within the system.

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

What is the difference between elastically/inelastically deformed?

A

elastically deformed=object returns to it original shape after the force is removed.
Inelastically deformed=objects does NOT return to its original shape

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

What happens once the limit of proportionality has been exceeded\?

A

Once the limit of proportionality has been exceeded doubling the force will no longer double the extension the relationship will become non-linear and curved
Force= spring constant x extension
F=ke

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

What happens to the particles in a fluid?

A

fluid is either fluid or gas

When particles move around in a container they collide and these collisions create a force to the surface.

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

What happens if there is a low atmospheric pressure?

A

greater the altitude ,the less dense the atmosphere lower the atmospheric pressure

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

What does pressure at a particular point in a column of liquid depend on?

A

height of the column above the point

density of liquid

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

Describe upthrust

A

the bottom surface has a higher pressure and creates a resultant force upwards
The upwards force exerted by a fluid on a submerged object is called up thrust

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

What is Distance?

A

Scalar quantity
how far an object moves
it does not take into account the direction

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

What is displacement?

A

Vector quantity
has magnitude this describes how far the object has travelled from the origin
it also has direction

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

What is speed?

A

measurement of how fast an object travels

scalar quantity

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

What is velcoity?

A

Vector quantity

when travelling in a straight line an object with constant speed also has constant velocity

17
Q

What is a Distance-time graph used for?

A

used to represent the motion of an object travelling in a straight line
If an object accelerates the line will be a curve

18
Q

What is velocity time graph used for?

A

used to find the acceleration of an object

19
Q

How does an object accelerate when it falls through a fluid?

A

when an object falls through a fluid
objects accelerate due to the force of gravity
as it speeds up the resistive force increase

20
Q

Do all object have momentum?

A

all moving objects have momentum but if it is not moving the momentum is 0

21
Q

What is conservation of momentum?

A

In a closed system the total momentum before an event is equal to the total momentum after the event

22
Q

conservation of momentum example

A

two cars travel at the same direction along a road.Car A collides with the back of car Calculate the velocity
of the car after the collision

momentum before collision-momentum A + momentum B
(mass A x velocity a) + (mass B x velocity of B)
(1200 x 20)+(1000 x 9)
24000 + 9000=33000kg m/s

momentum after collision=33,000kg m/s
momentum after collision = (mass A + mass B) x ( new velocity combined)
(1200 + 1000)=2200
33000/2200=15m/s

23
Q

centre of mass

A

The single point through which the weight of the object can be said to act.

24
Q

What do vector diagram show?

A

used to show the overall effect when more then one force acts on an object
OR can be used to show when a force is acting in a diagonal direction

25
Q

How do you draw a vector diagram?

A

forces are added together to find a single resultant force including both magnitude and direction
vectors are added heat to tail and arrows are drawn

26
Q

How do you draw a diagonal vector diagram?

A

diagonal line (FR)can be broken down to F1 and F2
F1 is the same length of FR in the horizontal direction
F2 is the same length of FR in the vertical direction

27
Q

Give an example of work done?

A

E.G work done to overcome friction causes an increase in heat energy.
Work done= Force x distance
W=fs
1 joule=1 Newton Metre

28
Q

Is extension directly proportional?

A

Extension of an elastic object is directly proportional to the applied force

29
Q

What happens if the spring constant is high?

A

higher spring constant, stiffer the string
amount of work done and energy store is equal
SPRINGS DO NOT GO PAST THE LIMIT OF PORPORTIONALITY.

30
Q

What happens of the pressure acts on a large area?

A

If the pressure act on a bigger area it will produce a larger force

31
Q

When is there less air above the surface?

A

At a high altitude there is less air above a surface than at lower altitudes so there is a smaller weight acting on the surface

32
Q

What does it mean if the column is high and the liquid is dense?

A

greater the pressure
greater the weight above the point
greater the force on the surface at that point

33
Q

In terms of upthrust what happens when an object is less dense that the liquid?

A

*displaces volume of liquid greater than its own weight so it will rise to the surface
*will float with some of the object remaining below
the surface

34
Q

How does an object sink or float?

A

If an object has a low density more of the object will remain above the surface
An object denser then its surrounding can not displace enough liquid to equal its weight so it will sink

35
Q

When does an object sink or float?

A

An object floats when its weight is equal to upthrust and sinks when the weight is greater then upthrust

36
Q

What factors affects speed?

A

Factors like age,fitness,distance affects the person who is walking,running,cycling

37
Q

What happens if an object does not travel in a straight lien?

A

*the speed will be constant but the velocity will change as the direction changes

38
Q

What happens if an object is moving in a circle?

A
  • the direction is constantly changing so it constantly changing velocity
  • it is accelerating even if it travelling at a constant speed
39
Q

What happens when resultant force reaches 0 in terminal velocity?

A

resultant force reaches zero when the resistive forces balance the force of gravity. At this point the object will fall at a steady speed and its called terminal velocity

physics (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions