Brainscape's Knowledge GenomeTM

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


See full index

Physics > Mechanics 1 > Flashcards

Mechanics 1 Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

Definition of a vector

A

a quantity with both magnitude and direction

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

3 examples of vectors

A

displacement
velocity
acceleration

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

Definition of a scalar

A

a quantity with magnitude but not direction

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

how do you represent a vector

A

draw an arrow

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

u

A

initial velocity

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

v

A

final velocity

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

s

A

displacement

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

t

A

time

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

a

A

acceleration

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

definition of displacement

A

the distance travelled in a particular direction

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

definition of speed

A

distance / time

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

definition of velocity

A

displacement / time

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

definition of acceleration

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

what do you have to do if you give a definition in algebraic form

A

you must explain the notation

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

distance time graph, at the origin; the initial speed is zero

A

false

the car passed through the starting point while moving

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

time interval between consecutive dots on a ticker-tape-timer

A

0.02 s

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

how to calculate velocity on a ticker-tape-timer

A

distance of 6 over 0.02 by 6

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

what does uniform velocity on a ticker-tape-timer

A

dots are equal measure apart

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

why do we use more than one space on a ticker-tape-timer when it is uniform velocity

A

get an average

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

why do we use more than one space on a ticker-tape-timer when it is non-uniform velocity

A

we are supposed to get an average of 5-6 spaces

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

how to calculate acceleration on a ticker-tape-timer

A

find velocity

acceleration = v-u over t

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

what is t when calculating acceleration on a on a ticker-tape-timer

A

0.02 x amount of dots you used

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

how does data logging work?

A

an electromagnetic wave from a sensor reflects offa moving trolley

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

what can data logging be used to measure

A

velocity

acceleration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

acceleration due to gravity

A

(-) 9.8 m/s squared

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

formula used to calculate acceleration due to gravity in the experiment

A

s= ut + 1/2at squared

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

2 note on accuracy for measuring acceleration due to gravity experiment

A

do it 5 times and get an average

avoid error of parallax when measuring with a metre stick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

slope of a 2xdistance time squared graph

A

would give you acceleration (due to gravity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Newton’s first law

A

a body continues in a state of rest or uniform motion in a straight line unless a resultant external force acts upon it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

according to newton’s first law, what will happen to a stationary object

A

it will remain at rest forever unless a resultant external force acts on it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

according to newton’s first law, what happens to an object moving in a straight line

A

it will keep travelling in a straight line at constant speed and will do so forever unless a force acts on it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

all objects have inertia which is…

A

refusal to change their state of motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what is a measure of a body’s inertia

A

mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

mass is measured in

A

kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what is the purpose of seat belts in cars

A

to overcome the inertia of moving passengers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what does the law of friction usually do

A

it opposes the motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

1 bad thing that friction causes

A

the wearing in machines due to moving parts rubbing together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

1 way to reduce friction

A

using oil, lubricants etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

1 benefit of friction

A

brakes on cars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

definition of friction

A

a force that opposes the relative motion of two objects in contact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

momentum

A

mass multiplied by velocity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

p =

A

m x v

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

p

A

momentum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

m

A

mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

v

A

velocity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

is momentum a vector or a scalar quantity

A

vector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Newton’s second law

A

When a resultant external force acts on a body, the rate of change of momentum of the body is proportional to the force and takes place in the direction of the force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Force ∝

A

the rate of change of momentum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

F ∝ (1)

A 
t
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

F ∝ (2)

A

(u-v)
—– x m
t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

F ∝ (3)

A

ma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

F =

A

Kma

53
Q

K, constant for force

A

1

54
Q

k=1 so F=

A

ma

55
Q

force, vector or scalar

A

vector quantity

56
Q

mass 3

A

a scalar quantity, constant value, unit is kg

57
Q

weight 3

A

a vector quantity, variable depending on height above ground, unit is newton

58
Q

Definition of mass

A

a measure of a body’s inertia

59
Q

Definition of weight

A

the force of gravity acting on a body

60
Q

Newton’s third law

A

To every action there is an equal and opposite reaction. Action and reaction do not happen on the same body

61
Q

if someone is in a lift and F= 0

A

they experience a feeling of weightlessness in zero gravity

62
Q

State the law of conservation of momentum

A

when two or more bodies interact in a closed system, the total momentum of the bodies before the interaction equals the total momentum of the bodies after the interaction

63
Q

conservation of momentum equation

A

m1u1 + m2u2 = m1v1 + m2v2

64
Q

Definition of work

A

force multiplied by displacement

65
Q

W =

A

F x s

66
Q

W

A

work

67
Q

F

A

force

68
Q

s

A

displacement

69
Q

is work a vector or scalar

A

scalar

70
Q

unit of work

A

J

joule

71
Q

1J =

A

1N x 1m

72
Q

Definition of energy

A

the ability to do work

73
Q

unit of energy

A

J

joule

74
Q

Conservation of energy

A

Energy cannot be created or destroyed but may be changed from one form to another

75
Q

Definition of kinetic energy

A

the energy an object has due to its motion

76
Q

Ek =

A

1/2 m v squared

77
Q

Definition of potential energy

A

the energy an object has due to its position, shape or state

78
Q

E p =

A

m g h

79
Q

Definition of power

A

the rate at which work is done

80
Q

unit of power

A

W watt

81
Q

P =

A

W/t

82
Q

power =

A

work over time

83
Q

1W =

A

1J /1s

84
Q

percentage efficiency =

A

Po/Pi

85
Q

Po

A

power output

86
Q

Pi

A

power input

87
Q

electricity is used to rotate an electric motor

A

electrical to kinetic

88
Q

the food we eat is used to give to energy to move

A

chemical to kinetic

89
Q

electricity is used to power a speaker in a music system

A

electrical to sound

90
Q

electricity is used to recharge a battery in a phone

A

electrical to chemical

91
Q

renewable sources of energy

A

forms of energy that will not be used up

92
Q

2 examples of renewable energy

A

hydroelectricity

solar energy

93
Q

what is hydroelectricity

A

converting the kinetic energy of flowing water into electricity

94
Q

what is solar energy

A

using the suns energy to heat water (solar panel) or to generate electricity (solar cell)

95
Q

non-renewable sources of energy

A

forms of energy that will not be used up

96
Q

4 non-renewable sources of energy

A

oil
gas
turf
coal

97
Q

how does the sun get it energy

A

mass is converted to energy in a process called nuclear fusion

98
Q

What is the resultant force when 12 N east is added to 7.5 N west?

A

n

99
Q

What is the resultant when a horizontal force of 12 N is added to a vertical force of 5 N

A

h

100
Q

What is the resultant force when 6 N east, 6 N south and 6 N north west are added?

A

h

101
Q

A boat is moving with a velocity of 15 m/s in a direction of 42º north of east. Calculate the components of this velocity heading north and heading east.

A

h

102
Q

A river flows at 5m/s south. A boat has a speed of 7m/s. The river is 300m wide. 1. If the boat leaves the bank and heads straight across, what direction will it go and how long will it take to get there?
2. if the boat leaves a point and wants to arrive directly across from that point, what direction will it travel and how long will it take to get to the other side?

A

n

103
Q

An object of weight of 900N lies on a surface inclined at 10º above the horizontal, find the component weight acting along the inclined surface

A

j

104
Q

a pendulum bob is displaced to one side so that the string makes an angle of 15º to the vertical. The weight of the bob is 12 N. Calculate the component of this weight that causes the bob to move

A

h

105
Q

An object starting from rest reaches a speed of 20 m/s in 4 seconds. Calculate the acceleration and the distance travelled.

A

h

106
Q

A car started from rest reaches a speed of 12 m/s in 3 seconds. It then travels at this speed for 10 seconds. find the total distance traveled

A

f

107
Q

When the brakes are applied to a train it takes 2 minutes to stop while moving a distance of 2 km. If the deceleration was constant, find the initial speed.

A

e

108
Q

a car passes a point “A” travelling at a uniform speed of 36 m/s along a straight road. A second car initially at rest leaves “A” 7 seconds later. This car accelerates at 2 m/s along the same straight road. Calculate the time it takes the second car to catch up on the first car.

A

j

109
Q

A man rows a boar downstream from “p” to “d” in a time of 40 minutes

  1. calculate the average speed while moving from “p” to “d”
  2. Calculate the average speed while moving from “d” to “p”
  3. calculate the average speed for the return journey (up and back)
A

jkl

110
Q

a car travels at 24 m/s for 5 seconds. the brakes are then applied and the car comes to rest in a further 10 seconds. Draw a velocity-time graph of this information and use the graph to calculate the total distance travelled.

A

j

111
Q

A car travels at 10 m/s having accelerated from rest for 4 seconds. It maintains this speed for 1 minute. It then takes 2 seconds to stop the car. Draw a velocity-time graph of this information and use the graph to calculate the total distance the car travelled.

A

g

112
Q

A car starts from rest and accelerates at 4 m/s^2 for 5 seconds. It then travels at a uniform speed for the next 12 seconds. It then decelerates to rest in a further 8 seconds. Draw a velocity-time graph of this information and use the graph to find the total distance travelled and the average speed for the entire journey.

A

l

113
Q

A sprinter can start with a velocity of 6m/s. He then runs with a uniform acceleration. Using a velocity - time graph calculate the greatest velocity reached if he can run 100m in a time of 10 seconds.

A

b

114
Q

An object is thrown vertically upwards at a speed of 30 m/s
1. calculate the maximum height reached
2. the speed when it is half way up to the maximum height
3. the time to reach half this maximum height
4. the times when its height is 40m
(let g=9.8 m/s^2)

A

g

115
Q 
An object falls from rest at a height of 200m above ground level. What is the height of the object after 5 seconds ?
(let g=9.8 m/s^2)
A

h

116
Q

A small ball is thrown vertically upwards with a speed of 30 m/s from the roof of a building which is 20 metres high.
calculate:
1. the time to reach the maximum height
2. the total time it takes for the ball to reach the ground
(let g=9.8 m/s^2)

A

t

117
Q

An object is thrown vertically upwards. Its speed is 32m/s when it has reached half its maximum height. Calculate:
1. the value of maximum height
2. the speed of the object 1 second after it was initially thrown upwards
3. the average speed for the first half second
(let g=9.8 m/s^2)

A

h

118
Q

Calculate the momentum of a 240 gram object moving at 45 m/s north

A

k

119
Q

Calculate the weight of 900 grams (let g=9.8 m/s^2)

A

s

120
Q

A bullet of mass 12 grams enters a piece of wood travelling at a speed of 500 m/s . It exits from the piece of wood at a speed of 190 m/s. Calculate the average force exerted by the wood on the bullet if the thickness of the wood is 5cm.

A

h

121
Q

A person of mass 55 kg stands on a weighing scales on the floor of a lift. The weighing scales is calibrated in newtons. Calculate the reading on the scales when

  1. the lift is stationary
  2. the lift moves upwards with a uniform speed of 3 m/s
  3. the lift accelerates upwards at 3 m/s squared
  4. the lift accelerates downwards at 3 m/s squared
  5. the support cable snaps and the lift falls freely under gravity
A

b

122
Q

An object of mass 8 kg moves at a speed of 3 m/s to the right. It collides with a second object of mass 6 kg moving at 7 m/s to the left. As a result of the collision the speed of the second object us reduced by 5 m/s. Calculate the velocity of the first object after the collision.

A

l

123
Q

A stationary spacecraft of mass 600kg expels 5kg of exhaust gases at a speed of 120 m/s. Calculate the recoil speed of the spacecraft.

A

k

124
Q

A sphere “A” of mass m rolls along a frictionless plane with a speed of 0.4 m/s. It collides with a sphere “B” of mass 2m which is at rest. After the collision the spheres move in the same direction as shown. The initial speed of sphere “A” is 0.1 m/s. Calculate the speed of B after the collision.

A

c

125
Q

A body of mass 80 grams and travelling with a speed of 5 m/s collides with another body if mass 200g at rest . The bodies coalesce on impact. Calculate

  1. The change of momentum for each body
  2. The average magnitude of the force exerted by each body on the other if the change of momentum occurs in 0.1s
A

h

126
Q

Calculate the work done to stop a 50kg object moving at 100 m/s in a time of 15 seconds

A

j

127
Q

A man carries a 40kg object up 60 steps each of vertical height 25cm. Calculate

  1. The work the man does on the object
  2. The gain in potential of the object
  3. The average power if this happens in a time of 5 seconds
A

p

128
Q

A pendulum bob of mass 1.5kg is displaced to one side through an angle of 60º with the downward vertical. The length of a pendulum is 3m. The bob is released and swings downwards. As the bob through the lowest point of its swing. Calculate

  1. The speed of the bob
  2. The kinetic energy of the bob
A

d

129
Q

An electric motor has a power input of 90 W. It can lift 100kg through a height of 5m in a time of 1 minute and 10 seconds. Calculate the percentage efficiency of the motor.

A

x

Physics (11 decks)

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