Physics Flashcards

1
Q

What impacts gravitational field the most?

A

Radius

The bigger the radius the more the gravitational field will decrease

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2
Q

How to convert days into seconds

A

1) find out how many seconds are in a day by
24hr x 60 (to get min) x 60 (to get seconds)

2) multiply that total by the amount of days asked in the question

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3
Q

Conversion tips

A

1) Determine which unit is bigger and which is smaller
2) Use chart to determine what to multiply / divide by
3) if small -> large = divide
if large -> small = multiply

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4
Q

Gravitational field

A
  • Attraction acts to pull a smaller object towards s larger massive one.

Points towards the object (ex: arrows point towards the earth)

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5
Q

What happens to field strength if mass increases?
(look at formula to help you figure it out)
What happens to field strength if radius increases?

A

If the mass increases the field strength increases

If Radius increases the field strength decreases

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6
Q

Electrical field diagram

A

Negative = Charges attract towards
Positive = Charges attract away from

( santa’s elves turn bad and away from good)

(we can see this later when away from north pole and towards south pole in magnetic field strength)

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7
Q

Grounding

A

Providing a path for electrons to flow from an object towards the ground so that it becomes uncharged or neutral.

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8
Q

Magnetic fields: Ferromagnetic ( Strong magnets) where are the domains

A
  • tiny magnetic ( domains inside)
  • All magnets ( domains aligned)
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9
Q

Magnetic fields: what makes the Field strength increase and decrease

A

Decrease with distance (pulling apart)
Increase with strength of magnet

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10
Q

Magnetic fields: field lines

A

To determine direction use “north” test body

** Field lines go out of the north pole and into the south pole

(what happens to bad elves)

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11
Q

How does a motor work

A

1) As a current flows through the coil, a magnetic feild is generated

2) The magnetic field generated by the coil will interact with the permanent magnet.

3) Then can be used to make things spin and turn for different purposes ex: hair dryer

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12
Q

Motion cycle (when you have two the third is produced) What are the the three contents of this cycle.

A

1) Current / electrons (electrical field)

2) Magnet (magnetic field)

3) Motion / Movement

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13
Q

Generators

A
  • Opposite energy conservations as motors
    = generators convert mechanical energy into electric energy.

Motor produce mechanical energy
Generator produces electrical energy

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14
Q

List ways to make a stronger motor (x5)

A

1) Increasing number of coils
2) increase strength of magnet
3) changing magnet shape
4) increasing voltage
5) wrapping wire around metal

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15
Q

Alternating current ( + diagram)

A

= Electrons flow in both directions
(squiggly line diagram)
I
I vvvvvvvvvvv
——————-

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16
Q

Direct current ( + diagram)

A

= electrons flow in one direction in a current
(straight line diagram)
I
I —————–
——————

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17
Q

What do batteries create

A

Voltage
- Which is electrical potential energy that is available for work

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18
Q

What is resistance measured in

A

Ohms

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19
Q

Series circuit

A

Box circuit with no allies or pathways, have the most resistance (especially if theres more resistors)

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20
Q

Parallel circuit

A

Circuit with rows/pathways/allies within it, less resistance the more pathways there is.

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21
Q

3 ways we can be protected against electric shock

A

1) Fuses
2) Circuit breakers
3) Polarized Plugs

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22
Q

Fuses (what do they do)

A

If the current is too high \, ruse coordinator overheats and melts
as a safety precaution the circuit is ten broken to stop the current.

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23
Q

Circuit breaker

A

Opens circuit automatically if current is too high
If current rises above a safe level, breaker tips and circuit is broken

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24
Q

Ohm’s law ( what happens to the current if the voltage goes up?)

A

Current goes up volts go up

And as resistance goes up current goes down (resistors slow down current)

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25
What are transformers used for?
To **change** voltage & current of the electricity being delivered
26
What are transformers made of?
= 2 coils of insulated wire wrapped around an iron core.
27
What's the difference between primary vs secondary
Primary = receives input voltage Secondary = supplies the output voltage
28
Step up
- voltage is increased (higher in secondary voltage) - more secondary coils
29
Step down
- Voltage decreased - more primary coils - Higher current
30
How does a transformer work?
1) AC enters primary coil 2) causing a **change** in magnetic field which was magnified by iron core. 3) The change in magnetic field induces AC to second coil.
31
What principle used by transformers?
its called electromagnetic induction
32
What is currents relationship with resistance?
If Current goes up resistance goes down and vis versa. They have an opposite relationship.
33
Parts of motor: Armature
Metal loop (THAT SPINS) uses its arms to stay between curved pieces of metal.
34
Parts of motor: Brush
**Provides electrical contact.** Always maintain contact and allows commutator and armature to spin. (when you brush your hair you'll feel so good you may spin around)
35
Parts of motor: Commutator
Ring with gaps to help armature spin. interacts with permanent magnet. Communication circle may have some gaps, this one has two which allow the current to switch direction.
36
what kind of current is used in transformer
AC
37
What is EMR
EMR is a wave that consists of changing electric feilds and a changing magnetic feild that travels at a right angle.
38
Wavelength vs frequency
Wavelength = Length of one cycle (meters) (symbol = weird A) Frequency = # of cycles /second (hertz) (f)
39
Types of EMR: Radio Waves
- **Lowest** Energy - **Lowest** frequency - **Source** = Vibrations of electrons within electric circuits - Do **not** penentrate - Are **not** ionizing
40
Types of EMR: Microwaves
- **Source** = High frequency vibrations of electrons within specialized electric circuit. - **Hazardous** to Humans due to the high water content inside humans - Are **not** ionizing
41
Types of EMR: Infrared
- **Source** = Emitted from a HOT object - **Can** burn human skin - Are **Not** ionizing Ex: The heat we feel from the sunlight
42
Types of EMR: Visible light
**Source** = HOT objects such as sun, lightbulbs, and a fire. - **Can** burn through air as well as the lenses in our eyes - Are ** Not** ionizing
43
Types of EMR: Ultraviolet
**Source** = Very HOT objects such as the sun - Mediacal equiptment **Sterlizers** - **Can** burn ozone layer, as well as causing abnormal cell division (cancer) - ** Some** are ionizing UV light is why we wear sunscreen to protect us from the suns rays.
44
Types of EMR: X- Rays
**Source** is fast moving electrons striking a metal target, cna penetrate body tissue but not bones (thats why its used for examining bones) Ionizing: Yes Penetrate: Yes Example: Radiation therapy ^ l Do this in your notebook for all of them as review
45
Types of EMR: Gamma Rays
Source = Radioactive material Penetrate = Yes metals, and cell division Ionizing = Yes Applications = Sterilize food
46
Reflected Light
- Bounces off an object - A mirror is a perfect reflector
47
Law of Reflection
Angle of incidence is = to the angle of reflection (equal on both sides / same angle)
48
Total internal reflection
= No light rays are transmitted through the medium and totally reflected back into the water.
49
Refraction
= When EMR waves bend, when they go from one medium to another
50
Diffraction
The scattering of light as it passes by an obstacle - Can be applied to all EMR
51
Polarization
Confine a wave to vibrate only in one direction, helps reduce glare in sunglasses.
52
4 Steps on how stars are formed
1) All stars start out as nebula ( cloud of gas and dust) 2) The gas begins **collapse** and heat up due to its own gravitational attraction 3) Nuclear fusion when it gets really hot 4) EMR and energy is produced which prevents star from collapsing
53
Nuclear fusion
= 2 small nuclei join to form a larger nucleus releasing energy during the process - Energy released = EMR (makes stars shine) ---------Red stars are the coolest color and blue stars are the warmest-----------
54
what is a stars life cycle dependent on?
Original mass of the star
55
Types of stars: Low-mass star
Fact = spend most of life fusing hydrogen into helium (Spends the first part of life in nuclear fusion) **Sequence**= NEBULA , LOW-MASS, RED GIANT, EXPANDING SHELL OF GAS, WHITE DWARF R = Reindeer E = Erin (is) W= Wee Or REW
56
Types of stars: Intermediate-mass star
**Sequence**= NEBULA, INTERMEDIATE STAR, SUPERGIANT, SUPERNOVA, NEUTRON STAR S: Super Giant S: Sports N: News
57
What do all (mass) stars start off as?
Nebula
58
Types of stars: High-mass star
**Sequence**= NEBULA, HIGH-MASS STAR, SUPERGIANT STAR, COLLAPSING STAR, BLACK HOLE S = Super Giant C = Chicago B = Bear
59
What are telescopes used for?
Study things in space by collecting EMR
60
Types of Telescopes: Simple Refracting telescope (use what you already know about light)
= Magnifies an image by using lenses to bend light
61
Types of Telescopes: Reflecting telescope (use what you already know about light) What is the name of the popular large reflecting telescope?
If it has a mirror = reflecting telescope - magnifies by reflecting light = Hubble space telescope
62
Types of Telescopes: Radio (use what you already know about light)
= They detect and record radio waves coming from stars
63
Types of spectrums: continuous
ALL colors and wavelengths are present
64
Types of spectrums: Emission
Bright lines emitted from an *excited* gas under low pressure (was so excited it exploded with bright lines = emission)
65
Types of spectrums: Absorption
Has dark lines because wavelengths are being absorbed.
66
how do you analyze a spectrum?
= look at the bars and compare them to the reference/unknown llll llll - Unknown llll lll - Helium (yes) lll - Hydrogen (no)
67
Red Shifted spectrum
- Further away / Shifting away from earth = Longer / larger wavelengths & Lower frequency - Means the universe is expanding and is most commonly seen.
68
Blue Shifted Spectrum
- Closer / Shift towards earth = Shorter wavelengths & Higher frequency - Means the universe is contrating and is not commonly seen
69
What do the different colour of stars mean?
Blue = Hot Red = Cool
70
Motors vs Generators
Motors = Chemical potential -> Electrical -> Kinetic energy / spinning of armature Generators = Kinetic energy -> Electrical energy
71
Induction
The process of generating current in a conductor by placing it in a changing magnetic field. Picture of smpeter with a motor and how when the motor spins and interacts with the permanent magnet the current is generated.