Physics Review Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Significant Digits

A
  • Digits 1 to 9 are always significant digits
  • Leading 0’s are not significant, trailing zeros are always significant
  • When adding or subtracting numbers, the number of digits behind the decimal in the answer should be equal to the least number of digits behind the decimal in the question
  • When multiplying or diving numbers, the number of significant digits in the answer should be equal to the least number of significant digits in the least number
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Scalar Quantities

A

Have magnitude only and do not include direction
- Distance, speed, time, work, mass

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

Vector Quantities

A

Have both magnitude and direction
- Displacement, velocity, acceleration, force

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

Distance

A

Scalar quantity that describes the length of a path between two points. SI unit is meters (m)

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

Displacement

A

Vector quantity that describes the straight-line distance from one point to another, as well as direction. SI unit is second (m)

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

Time

A

Scalar quantity that describes a specific point in time. SI unit is second (s)

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

Speed

A

Scalar quantity that describes the distance travelled by an object during a given time interval. SI unit is meters per second (m/s)

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

Velocity

A

Vector quantity that describes the displacement of an object during a given time interval. SI unit is meters per second (m/s)

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

Acceleration

A

Vector quantity that describes any change in the velocity of an object during a given time interval. Non-uniform motion because velocity is not constant.

  • Although acceleration points in the same direction as the CHANGE in velocity, it’s not always in the same DIRECTION as the velocity itself
  • Acceleration in the same direction of velocity = Speeds up
  • Acceleration in the opposite direction of velocity = Slows down
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Force

A

Vector quantity that describes a push or pull that must be exerted on an object in order to make the object move. SI unit is newton (N) or kilogram meter per second squared (kg * m/s^2)

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

Issac Newton

A

Described the relation between force and motion, in his 3 laws of motion
1) Law of Inertia - Every object in motion will remain in motion and every object at rest will remain at rest unless acted upon by an outside force; friction and gravity
2) F=ma - Force needed to change an objects motion is proportional to its mass and its acceleration
3) Reactions - For every action there is an equal and opposite reaction

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

Force of gravity

A

The force of gravity acting on an object. SI unit is Newton (N) or kilogram meter per second squared (kg*m/s^2)
- Force of gravity on earth = 9.81 m/s^2

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

Work

A

Scalar quantity that describes the energy transfered to or from an object when a force is applied to move the object. Work is done when an object moves in the direction of the force that is being applied. SI unit is Joule or kilogram meter squared per second squared (kg * m^2/s^2)

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

Graphical determination of work

A

Total work done by the force can be determined from the area under the curve of a force vs. distance graph

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

Kinetic energy

A

The energy of motion

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

Bulk Kinetic Energy

A

Energy due to the motion of a whole object
- Larger the mass or faster the object, the more bulk kinetic energy it has

17
Q

Electric Energy

A

Energy carried by moving electric charges
- Eg. Lightning as a result of moving electrical charges

18
Q

Thermal Energy

A

Energy due to the random motion of the molecules that make up an object

19
Q

Sound Energy

A

Energy carried from molecule to molecule by longitudinal waves

20
Q

Radiant Energy

A

Energy that travels as electromagnetic waves
- Eg. Sun is our largest source of radiant energy

21
Q

Potential Energy

A

The energy that can be stored in an object for a long period of time. This stored energy can be transformed into a form of energy that can do work

22
Q

Gravitational Energy

A

Energy as a result of an object’s distance above the Earth

23
Q

Elastic Energy

A

Energy stored in an object when it is forced out of its normal shape

24
Q

Chemical Energy

A

Energy stored in molecules (bonds between atoms)
- This energy is released when a chemical reaction occurs and bonds are broken

25
Q

Nuclear Energy

A

Energy stored in the nucleus of an atom
- Released during nuclear fission, when a large nucleus breaks apart
- Released during nuclear fission, when small nuclei join together

26
Q

First Law of Thermodynamics

A

Energy is conserved in a closed system. This means that energy cannot be created or destroyed, only transformed from one form to another or from one object to another
- The total energy of the universe is constant

27
Q

Free Fall Question

A

Em = Ep + Ek
- When height is max, Ep = max, Ek = 0, Em = Ep
- When height is 0, Ep = 0, Ek = max, Em = Ek
- There is a middle point where Em = Ep + Ek
Em before = Em after
Ep + Ek = Ep + Ek
mgh + 0 = 0 + mv^2/2
gh = v^2/2
(masses cancel out in freefall questions)

28
Q

Four Elements Theory

A
  • All matter consists of a combination of four elements: earth, air, fire, water
  • When objects burn, the fire inside of them is released
29
Q

Phlogiston Theory

A
  • Substances that could burn contained an invisible fluid called phlogiston, that flowed out of an object when it burned
  • Problem: Theory implies that the mass should decrease when an object burns, but magnesium gains mass when it burns
30
Q

Caloric Theory

A
  • Caloric is a mass-less fluid found in all substances, that flows from one substance to another to another. The flow is always from warmer to cooler objects
  • Problem: When holes are bored into metal to make a cannon, the metals were not hot to start with but became hot afterwards
31
Q

Rumford’s Hypothesis

A
  • When holes are bored into metal to make a cannon, the mechanical energy is converted into heat, therefore Heat = Energy
  • Problem: Caloric theory was so popular that Rumford was ignored
32
Q

Mayer’s Hypothesis

A
  • Recognized that the body uses oxygen to break down food for energy, and that this same process provides heat. Discovered that bodies in colder climates use more oxygen and generate more heat than bodies in warmer climates. Further support to Rumford’s idea that Heat = Energy
  • Problem: Mayer was not schooled in math or physics so his ideas were overlooked because his presentation was poor
33
Q

Joule’s Theory

A
  • Proved the relationship between mechanical energy and heat, using the following experiment:
    1) Force of gravity causes the weight to fall
    2) Falling weight pulls on the string, which turns the drum
    3) Turning of the drum stirs the water
    4) The motion of the stirrer transfers energy to the water, which causes the temperature of the water to increase
  • Force of gravity indirectly does work on the water
    Ep (weight) → Ek (weight, drum, stirrer) → Thermal Energy (water)
34
Q

Kinetic Molecular Theory

A
  • The molecules of a liquid or gas are in constant random motion. Kinetic energy is the energy of motion. The molecules in a solid vibrate
  • As the molecules move in a straight line, they collide with each other and with the walls of the container
  • Heat - The transfer of thermal energy from one object to another
  • Temperature - The average kinetic energy of the individual atoms or molecules in a substance
35
Q

Steam Engine

A
  • Any machine that generates steam and converts the steam pressure into mechanical motion
    Heat → H20 (l) → H2O (g) → Pressure → Mechanical Motion
36
Q

Second Law of Thermodynamics

A

No process is 100% efficient. Some energy is always lost as thermal energy.