Physics Flashcards
What is a field?
a 3-D area that feels the effects of force
What properties do fields have?
All fields have a source, direction, and magnitude.
How many types of fields are there and what are they?
There are three types of fields: Electrical field, gravitational field, and magnetic fields.
True or False: You can observe a field indirectly
False
How do you determine the direction of the fields?
Test Objects
What kinds of test objects are there for gravitational fields?
Anything light (books) Any rock in space (moons)
What kinds of test objects are there for Electrical fields?
Hair
Ink
What kinds of test objects are there for magnetic fields?
Iron filings
Ions from the Sun
What is Gravitational Field Strength?
The amount of Newtons/kilogram a test body (a small mass) will experience at a certain distance from the source of the gravitational field.
What are field lines?
Non-intersecting lines, drawn in mapping a Vector
What is Gravitational Fields?
Space surrounding a mass. Gravity keeps objects on the earth (Gravity is actually infinite, but gets weak very quickly).
What characteristics are there in Gravitational Fields?
Source: any object with mass
Direction: always towards the center of the object (only pulls)
Strength measured in N/kg
What is Electrical Fields?
an electrical field is a region surrounding a changed object. Electrical fields are used in copiers and other electrical technologies.
How do objects become charged?
Recall atoms made of a “+” nucleus and “-” electrons orbiting the nucleus
Charges are neither created nor destroyed, just transferred
When one objects rub against another, electrons are transferred from one material to another
Conductors are materials that allow electrons to move freely (ex. Copper and aluminum)
Insulators do not allow electrons to move freely, but can have their charges build up (ex. Cloth, fabric)
What is Electrostatic Attraction?
Opposite charges attract and same (like) charges repel. The more charged an object is, the greater the force is repulsion or attraction.
What are Electrical Field Characteristics?
Source: any object with a charge
Direction: towards the negative charge
Both attract and repel
Strength: measured in N/C
What is Grounding?
Allows electrons to flow into the Earth
What are Lightning Rods?
Lightning Rods are connected to the ground to help direct electrons below the surface of the Earth.
True or False: A lightning bolt will always take the shorted path and will likely strike a tall conductor first
True
What is a Current?
Symbol is I and the units is Amps (Ampere’s) (A)
How many electrons (how much charge) passes a point in 1 second
What is Electrical Energy?
Energy due to a moving charge (voltage) (V)
What is Mechanical Energy?
Energy a moving object contains or due to its poisition
What is Chemical Potential Energy?
Energy contained in bonds of a chemical substance
How many and what kind of Circuit(s) are there?
2
Series and Parallele circuits
What is a series?
A circuit where there is a simple single loop. When one burns out they all die
What is a parallel circuit?
A circuit where there are loops within a loop. There are multiple pathways for currents to flow. When one burns out, the others keep working
What happens when a battery is connected to a series circuit?
Voltage adds up
What happens when a battery is connected to a parallel circuit/
Voltage is on average
What is a resistor?
A resistor is any device in a circuit that disrupts electron flow, generating heat (thermal heat) or light
What is resistors measured in?
Ohms
What are currents measured in?
Amps
What are energy sources measured in?
Volts
What are two forms of radiation that comes from the sun?
Solar wind particles and electromagnetic radiation (EMR)