Brainscape's Knowledge GenomeTM

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


See full index

B1 M2 - Physics > 2.2 Mechanics - Dynamics (Lvl 2) > Flashcards

2.2 Mechanics - Dynamics (Lvl 2) Flashcards

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

What is Newtons first law?

A

“a body at rest remains at rest and a body in motion continues to move at a constant velocity unless acted upon by an unbalanced external force”.

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

What is Newtons first law referred to as?

A

The law of inertia.

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

What does Newtons first law tell us?

A

It tells us what to expect in the absence of forces or if forces acting upon a body are balanced.

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

What is Newtons second law?

A

“The acceleration of an object produced by a force is directly proportional to the force, is in the same direction as the force, and is inversely proportional to the mass of the object”.

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

What does newtons second law state?

A

It states that an unbalanced or resultant force acting on an object will cause the object to accelerate in that direction.

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

What is the formula relevant to newtons second law?

A

F = m x a

F = resultant force
m = mass
a = acceleration.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is newtons third law?

A

“every action has an equal and opposite reaction”.

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

What is newtons third law referred to as?

A

The law of action and reaction.

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

What does newtons third law focus on?

A

Focuses on the fact that forces arise from the interaction of two objects.

When one object exerts a force on a second object, the second must exert an equal and oppositely directed force on the first.

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

What is known as the normal force?

A

The upward push of the surface itself on the body.

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

What is the unit of mass in the imperial system?

A

The Slug

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

What is the formula of mass?

A

m = W/g

M = mass
W = weight
g = gravitational acceleration.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is weight?

A

Is the gravitational force of attraction between the mass of the earth and the mass of a body.

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

What happens to the weight of a body when it is moved away from earth?

A

Decreases.

Due to the gravitational acceleration depending on the distance from the earths centre.

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

What is the difference between mass and weight?

A

The mass of a body is the same at any point of the universe, but weight depends on its position.

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

What is inertia?

A

The property of matter that causes it to resist any change to its motion in either direction or speed.

It is therefore the force resisting the acceleration.

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

How does mass effect interia?

A

The greater the mass, the greater the inertia.

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

What is work?

A

Its a force causing the movement or displacement of an object.

The greater the force, the greater the amount of work done.

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

What is the unit of work?

A

Joules.

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

What is the formula of work?

A

W = F x s

W = work
F = force
s = Distance moved.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is power?

A

A measure of the rate at which work is done or at which energy is converted from one form to another.

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

What is the unit of power?

A

Watt.

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

What is the formula of power?

A

P = W/t

P = power
W = work
t = time.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is energy?

A

The capacity to do work.

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

What does energy consist of?

A

Kinetic and potential energy.

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

What forms does energy come in?

A
  1. Potential energy
  2. Kinetic energy
  3. total energy
  4. Chemical energy
  5. Thermal energy.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is potential energy?

A

Energy a body has due to its position or condition, allowing it to do work when released.

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

What is the formula potential energy?

A

Ep = m x g x h

Ep = Potential energy
m = mass
g = gravitational acceleration
h = height.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is kinetic energy?

A

Energy a body has due to its motion. It is the work needed to accelerate a body from rest to a velocity.

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

What is the formula for kinetic energy?

A

Ek = 1/2 x m x v^2

Ek = kinetic energy
m = mass
v = velocity.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is total energy?

A

The sum of all different forms of energy in a system.

32
Q

Energy can be transferred from one form to another, but what can not happen to energy?

A

It cannot bee destroyed.

33
Q

What is chemical energy?

A

Is the energy stored in the chemical bonds between atoms.

34
Q

What is chemical energy a form of?

A

Potential energy.

35
Q

How may chemical energy be used?

A

It can be released or consumed during a chemical reaction when bonds are broken or new bonds formed.

36
Q

What is thermal energy?

A

Energy a body has due to kinetic energy and potential energy of its molecules.

37
Q

What is thermal energy sometimes referred to as?

A

Internal energy.

38
Q

What is the type of energy called, where there is a flow of energy between two bodies due to difference in temperature?

A

heat or heat energy.

39
Q

Heat is often generated when…?

A

Converting energy from one form to another.

40
Q

What is efficiency?

A

The ratio of useful work done by the machine to the total work put into the machine.

41
Q

What is the formula for efficiency?

A

ƞ = Eout/Ein x 100

ƞ = efficiency
Eout = useful energy output
Ein = total energy input.
42
Q

What is momentum?

A

A vector quantity that describes mass in motion.

43
Q

What two variables affects an objects momentum?

A

Mass and velocity.

44
Q

What is the formula for momentum?

A

p = m x v

p = momentum
m = mass
v = velocity.
45
Q

When is momentum conserved?

A

In collisions and explosions.

46
Q

What does it mean when momentum is conserved?

A

The total momentum before an event equals the total momentum after the event.

47
Q

Which of Newtons laws helps derive the following equation “m1u1 + m2u2 = m1v1 + m2v2” for conservation of momentum?

A

Second and Third law.

48
Q

What is a collision?

A

An event when two or more bodies collide and exert forces on each other over a short space of time.

49
Q

What is an elastic collision?

A

An event in which kinetic energy and momentum are conserved and the two bodies bounce off each other.

50
Q

When is all the kinetic energy conserved?

A

In a perfectly elastic collision.

51
Q

What is an inelastic collision?

A

An event in which the kinetic energy is not conserved.

52
Q

What happens in a perfectly inelastic collision?

A

The two bodies stick together after colliding.

53
Q

How could the conservation of momentum equation be simplified in an inelastic collision?

A

m1u1 + m2u2 = (m1 + m2) v.

54
Q

How are signs for velocities important?

A

They show us the direction of the bodies.

-ve west/south
+ve east/north.

55
Q

What is an impulse?

A

Is something that changes the momentum of a body.

A force acting for a period of time.

Vector quantity that produces an equivalent vector change in its linear momentum in the same direction.

56
Q

What is the formula for impulse?

A

J = F x t

J = Impulse
F = force
t = time.
57
Q

During the calculation of impulse, if the force were to change over the time interval, what do you do?

A

Calculate using the average net force for the time interval.

58
Q

What is a gyroscope?

A

An instrument that contains a rotor, rating about an axis at high speed.

59
Q

What two important properties does a gyroscope gain from its construction?

A
  1. Rigidity

2. precession.

60
Q

What is rigidity also referred to as? (gyro)

A

Gyroscopic intertia.

61
Q

Which of newtons laws applies to gyroscope rigidity?

A

First law.

62
Q

What factors affect the rigidity of the spinning rotor in a gyroscope?

A
  1. Rotor mass
  2. effective radius at which the mass acts
  3. speed of rotation
  4. bearing friction.
63
Q

What is gyroscopic precession?

A

When an external force is applied to change the direction of the rotor spin axis, the gyro resists the change and moves the forces at right angles to the direction originally applied.

64
Q

What is friction?

A

The force resisting the relative motion of materials rubbing against each other.

65
Q

What are the different kinds of friction?

A
  1. Starting friction (static friction)
  2. Sliding friction
  3. Rolling friction.
66
Q

What is the formula for friction?

A

F = µ x N or F = µ x W

F = friction
µ = coefficient of friction
N = normal friction.
W = weight
67
Q

What is starting friction?

A

Its present when a body is at rest and just begins to move under the application of a force.

68
Q

What is starting friction also to referred as?

A

Break-away force.

69
Q

What is starting friction proportional to?

A

The weight of the body.

70
Q

What does starting friction depend on?

A

The material of the surface that a body is on.

71
Q

What is sliding friction?

A

When a body slides over another surface.

72
Q

When is sliding friction produced?

A

When an object has been set in motion, sliding over another surface.

73
Q

What is the difference between sliding and starting friction?

A

Sliding friction is always less that starting friction.

74
Q

What is rolling friction?

A

Is present between a rolling body and the surface on which it rolls.

75
Q

What is the difference between sliding and rolling friction?

A

Rolling friction is much smaller than sliding friction.

76
Q

What does every pair of flat surfaces have? (friction)

A

Two different coefficients

one for starting
one for sliding.

B1 M2 - Physics (9 decks)

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