Physics Unit Final Flashcards
what do you do if a question comes in scientific notation
answer in scientific notation
what two types of graphs can be used for uniform motion
distance-time graph and speed-time graph
what is the line of best fit on a distance time graph showing unirfomr motion
a stright line with a positive slope
what does the slope of a distance-time graph fepresent
the speed of an object
what does the line of best fit in a speed-time graph depicting uniform motion look like
a horizontal straight line
what does the line of best fit on a speed-time graph indicate when the object is travelling in uniform motion
that as time increasees the speed of the object remains constant
what does a slope of 0 meanm in a distance time graph
there is no motion
how do you determine the distance travelled by the object in a speed-time graph
calculate the area under the line of the graph
what two types of graphs can be used to analyze average velocity
position-time graph, velocity-time graph
when do you not need to indicate direction when solving for a vector quantity
if you are just aksed for a magnitude
what is the simplest type of motion
uniform motion
what is the most common type of motion
acceleration
what is the line of best fit look like in a position-time graph showing acceleration
a smooth curve
what is the typical pattern of motion for an object
an ‘s’ like curve
what does the slope of a velocity-time graph indicate
rate of acceleration
what does the line of best fit look like in a velocity-time graph for an object in accelerated motion
a straight line with an increasing or decreasing slope
what happens if all the forces on an object are balanced
the object doesn’t move
what does everything at rest have acting on it
balanced forces
what is force
a push or pull on an object
when will an object move
when an unbalanced force is applied to it over a given distance
what happens to an object in uniform motion if forces are applied
it will go through acceleration and either increase or decrease in velocity
when do all objects tend to remain in uniform motion or stay at rest
in the absence of any external unbalance forces
what happens if there is no force acting on an already moving object
it will keep moving
what happens when something does work on an object
energy is transferred to that object
what are the three conditions for work to occur
there must be movement, there must be application of force, the force and distance the object travels must be in the same direction
are energy and work the same thing
yes
what happens when a body does work on an object
the body doing the work loses energy and the object that has work done to it gains energy
whats chemical energy
potential energy stored in the chemical bonds of compounds that is released when bonds are broken
what is occurring during an energy transfer between objects
one object is doing work on the other object
what is electircal energry
work done by moving charges in the form of flowing electrons in currents
what is nuclear energy
potential energy stored in the nucleas of an atom that is released when the atom is split or when two nuclei of atoms combine
what is solar energy
energy that results from a ydorgen-hydrogen nulcear fusion reaction with the release of nuclear energy that can be converted into other energy forms
whats nuclear fission
the splitting of the nucleous of an atom
what is nuclear fusion
when the nuclei of two atoms combine
what two types of energy can be observed in nature
kinetic energy and gravitational potential energy
what is earths acceleration due to gravity
9.81 m/s2
if you are given two heights in a word problem, which one should you use
the vertical one, or the one that is straight up
when plotting a speed-time or velocity-time graph how should you connect the dots
using a line of best fit
what happens to an object if it’s falling
all of its potential energy from the top will be converted to kinetic energy
what can you use the pendulum theory for
to find the speed of an object at the bottom of its course right before it hits the ground
what word often indicates the input of energy
consumes
what word often indicates the output of energy
work
when is potential energy useful
when it is converted into some other form of energy
what is the law of conservation of energy state
energy cannot be created or destroeyed. it can only be transformed from one form to another, and the total amount of energy never changes
what has to happen in order for the law of conservation of energy to work
the energy lost by one system has to be gained by the other
how does a pendulum work
at the top it has full gravitational potential energy and as it swings down in an arc that energy begins to convert to kinetic energy till the pendulum gets to the bottom of the arc at its maximum speed and is converted fully into all kinetic energy
what do you need to look for when solving a pendulum problem
a vertical height
what are the three things that show that an energy conversion has occurred
change in shape, change in temperature, motion
whats a system
the object or objects involved in the energy transfers
whats an open system
system that exchanges both matter and energy with its surroundings
whats a close system
one that cannot exchange matter but can exchange energy with its surroundings
whats an isolated system
one that cannot exchange either matter or energy within its surroundings
what is the difference between heat and work
work involves the movement of matter from one location to another whereas heat is a transfer of thermal energy from one location to another
what are the two ways the energy of a system can be increased
heat can be added or work can be done on the system
what is the first law of thermodynamics
the total energy, including heat, in a system and its surroundings, remains constant. whenever heat is added to a system, it transforms into an equal amount of some other form of energy.
what would happen if no energy is converted to other forms
the machine would operate indefinitely
is it possible to create a perfect machine
no
what is the second law of thermodynamics
heat always flows naturally from a hot object to a cold object, but never natural flows from a cold object to a hot object
whats energy input
the initail energy source
whats useful energy output
the desired energy needed to do the work
whats useful work output
the work the machine is supposed to do
whats a solar energy source
those that are derived either directly or indirectly from the energy of the sun
whats a non-solar energy source
sources that have no relationship to the sun
what are renewable energy sources
ones that are continually and infinitely available or can be replaced in a reasonable length of time
whats a non-renewable energy source
sources that are limited and irreplaceable
what does a position-time graph measure
displacement
what does a velocity-time graph measure
distance
what does it mean if there is no displacement
no motion
what does a negative velocity mean
you are going that speed in. different direction
