physics final
a car goes from 0 m/s to 10 m/s in 1 second, moving along the negative x-axis. what is its acceleration
-10 m/s^2
a car starts with a velocity of 20m/s and reach to a stop in 5 seconds. the average acceleration of a car is
-4.0 m/s^2 0-20/5 = -4
one inch equals
0.254 centimeters
if 2 coulomb of charge flows through a wire in 10 seconds, the current in the wire is
0.2A, current = charge/time
everyone receives background radiation. this comes from various sources, the ground, medical procedures, radon in the air. on average, people in the US receive about
0.62 mrem of radiation per year
a student releases a ball form rest on an inclined plane and measures that it travels a distance of 5m in a time of 2.0s. the acceleration of the ball is
1.25 m/s squared. 2.5-0/2 = 1.25
a centimeter is
1/100 as long as a meter
a car is moving on a highway with a speed of 60 m/s. 5 seconds later the car is moving at 10 m/s in the same direction. the car's acceleration is
10 m/s squared - magnitude is only being asked here. 10-60/5
what is the acceleration of the following system
10 m/s^2 ?
I have a power outlet with V = 220. a current of 22 ampere is flowing through the circuit connected to the outlet. what is the resistance of the circuit?
10 ohm, v=ir
an 8 kg ball is rolling on a flat surface with a speed of 5m/s. the objects kinetic energy is
100 J
if 10 coulombs of charge flows through a wire in 1 second, the current in the wire is
10A
what is the total resistance of 3 40omega bulbs connected together by a wire thats attached to a battery
120 - add them all together
how much force is needed to accelerate a 3kg skateboard at 5m/s^2
15 (5x3)
Find the total resistance of the following
160 - add 50 + 15+95
if you are standing 2 feet from a plain mirror and looking into it, the image you see will be ___ feet away from the mirror on the other side
2 feet
calculate the mass of an object if it took 20 N to rotate it in a circle with a radius of 2 meters with a velocity of 4m/s
2.5 kg
a student releases a ball from rest on an inclined plane and measures that it travels a distance of 10.0 m in a time of 4.0s. the average speed of the ball is
2.5 m/s
a student releases a ball from rest (zero) on an inclined plane and measures that it travels a distance of 5m in a time of 2.0 s. the velocity of the ball after 2 seconds is
2.5 m/s v = displacement/time. 5/2 = 2.5
larrys total energy (KE + PE) is 2000 J as he reaches 100 m above the ground in a sky diving airplane. what is larrys gravitational potential energy when he begins to jump at rest from the airplane at an altitude of 100 m
2000 J
what is the acceleration of the following system
24 m/s^2 (8x3)
a great white shark can swim with a speed of about 16 meters per second. convert the sharks speed to miles per hours.
36 mph
a car starts from rest and reaches +20 m/s in 5 seconds. the average acceleration of the car is
4.0 m/s^2 20-0/5
calculate the centripetal force required to make a 5 kg ball move 4 m/s in a circle with a radius of 2 m
40N
which of the following answers is closest to the weight on the earths surface of a woman whose mass is 60kg? consider gravitational acceleration as 10 m/s^2
600N
find the total resistance of the following circuit
75 (idk)
a ball is thrown upward in the air with an initial velocity of 40 m/s. how long does it take to reach back to the point it was thrown from
8 seconds
if your mass on the earth is 85 kg then your mass on the moon would be
85 kg
which of the two signs shown below would indicate the greatest danger?
B - danger 10,000 V - more power
which of the three arrangements shown below will light the bulb?
B&C - wires touching the north and sound poles of the battery
the field lines due to two spheres with unlike charges are shown by
C,as long as the force is moving left with unlike charges
knowing what you know about uniform circular motion, and physics, when a NASCAR race car speeds around a circular track at 160 mph what keeps it from flying off the sides of the track?
Frictional force
the MKS (SI) unit of fore is the
Newton (N)
what types of imaging techniques uses gamma waves
PET scans
what object experiences non uniform circular motion
a car speeding up as it turns left
what object experiences uniform circular motion
a car traveling around a roundabout at constant speed
an object undergoing free fall experiences
a constant acceleration
imagine that this time you were aboard the international space station while swinging a rock on a rope around in a circle quickly (so you can neglect the effects of gravity) swinging it around in a circle very quickly. Suddenly, the rope breaks. what did the path of the rock look like before it hit the ISS window a few feet away?
a line
Assume that some charge flows within a copper wire. the moving charge will generate
a magnetic field
you place a permanent magnet on your desk. the magnet will generate
a magnetic field
when a glass rod rubbed with a silk acquires a positive charge, the silk acquires
a negative charge
an electron in a neutral calcium atom gains enough energy to move away from the calcium atom. the calcium atom becomes
a positive ion
A quantity that is a measure of how the velocity of a body changes with time is
accelaration
the force of friction
always opposes motion
a reporter at the newspaper says that she saw a full moon last night. that statement is most likely
an actual observation of the natural world
imagine you attached a rock to a rope and were swinging it around in a circle very quickly. suddenly, the rope breaks. what did the path of the rock look like before it hit the ground?
an arc
you place a permanent magnet on your desk and you attach it to a rotating shaft. the magnet will generate
an electric and a magnetic field
what is newtons first law of motion
an object in motion will stay in motion and an object at rest will stay at rest unless acted upon by an external unbalanced force
what are possible representations of electric field lines
any that don't overlap. They are parallel, moving in opposite directions, or connecting with an opposite charged ion.
the magnetic field lines produced by a current in a straight wire
are directed in concentric circles around the wire. they begin on one side of the wire and end on the other side of the wire
if no force is acting on an object, the object is
at rest of moving with a constant velocity
a pendulum moves with the greatest velocity
at the bottom of its swing
a ball is thrown straight up. it reaches its highest point and then falls back. which of the following is the correct statement?
at the highest point in its motion, the balls velocity is zero
a constant force F acts on block 1 with mass m and the same constant force F acts on block 2 with mass 2m. which graph correctly represents the accelerations of the blocks?
b - lines are parallel and apart at appropriate spots on the graph. no curves and they are not touching each other
the number of electrons delivered daily to an average american home by an average power utility in the mid 1980s was
billions of billions,
if an object absorbs light in all wavelengths, what color does it appear to be
black
the diagram shows the positions at 0.05 sec intervals of two balls moving left to right. are either or both balls accelerated?
both are accelerated. even though one appears to slow down and one is speeding up, they are both accelerating.
if a feather and a brick are both dropped form the same height at the same time in the classroom
both experience the acceleration due to gravity which is 9.8 m/s^2
in a laboratory on earth, all the air is pimped from a large tube. a feather and a steel ball are simultaneously released from rest inside the tube. what happened next?
both objects fall and hit the bottom at the same time
electrons move in an electric circuit
by interacting with an established electric field
what is the name of the force that keeps an object in circular motion
centripetal force
a car driver takes turn 1 at daytona international speedway at a steady 120 mph all the way through the turn. the radius of this turn is 1000 feet. which statement is true
change of direction at constant speed means a change in velocity
to save on electricity and eliminate heat in the kitchen, you would like to build a solar cooker. which type of mirror would work best?
concave
what type of lens is on the ray diagram below
concave
what type of lens is used to correct nearsightedness
concave
projectile motion is characterized by
constant acceleration in both the x and y directions
when speed and direction remain the same throughout a motion, this is called
constant velocity
what type of lens is a magnifying glass?
convex
a closed path that electric current follows
current
the ampere is a unit that expresses
current
the number of electrons flowing is called
current
which correctly represents the orientation of the electric field, magnetic field, and direction of propagation for x ray wave
d - BEV arrows pointing north (B) east (E) and southwest (v)
during the first second after an object dropped form rest and experiences free fall its displacement
decreases by 4.9 m
what is the difference between distance and displacement
displacement is a vector and distance is scalar
average speed is calculated by
dividing the distance traveled by the elapsed time
a body released from rest falls with an acceleration of 9.8 m/ssquared. if the same body is thrown upward at an angle, air resistance is negligible, the acceleration after release will be
downward and equal to 9.8 m/s squared
the value for the acceleration due to gravity is ms-2
downwards 9.8
according to keplers first law all planets have orbits about the sun that are
ellipses
the magnetic field lines of a bar magnet
emerge from the north pole and go into the south pole
the magnetic field of a bar magnet
emerge from the north pole and go into the south pole
the point where rays intersect when leaving the lens, if they were traveling parallel to the axis when they entered the lens, is called the
focal point
what is newtons third law of motion
for every force of action, there is an equal and opposite force of reaction
what is the simple equipent to demonstrate the earths rotation
foucault pendulum
the number of waves that pass by in a second is known as the waves
frequency
the figure below shows the orbit of a comet around the sun. the comet has the greatest velocity when traveling
from a to b (wherever the ball is closest to )
which of the following electromagnetic wave has the highest frequency
gamma ray
which of the following has a higher frequency than visible light
gamma waves
the speed of light in vacuum is
greater than the speed of light in glass.
which of the following power generation schemes does involves a turbine
hydroelectric power
which of the following statements is an observation of the natural world
i saw the moon rise at 6:52 am yesterday
in most households, power outlets have a voltage of 110 V because
if our body were connected by accident to a power outlet, a maximum of 100 mA would flow through it, which is not enough to damage the heart
imagine you attached a rock to a rope and were swinging it around in a circle very quickly. if you could keep the speed of the rock constant as you pulled the rope in, what would happen to the force transmitted to you by the rope?
increase inversely with the distance
a freely falling object neglecting air resistance has its velocity
increasing linearly with time
which quantity is the highway patrol more interested in
instantaneous speed
the following quantities relate to the rate of change of position. which pair will always have the same magnitude?
instantaneous speed and instantaneous velocity.
suppose a graph of distance traveled by a body versus time is constructed. the slope of the graph at any point may be identified with
instantaneous velocity
a scientific law
is a generalization based upon experiments or observation
The speed on an object in uniform circular motion
is directed tangent to the circle
in one dimensional motion, the average speed of an object that moves from one place to another and then back to the original place has which of the following properties?
it can be positive, negative or zero
the graph for position vs time is given for a car. what can you say about the velocity of the car over time. graph shows it arching
it slows down all the time
after it passes the peak of the path of its motion an object thrown upward has
its velocity directed downward and its acceleration directed downward
just after it is released, an object thrown upward has
its velocity directed upward and its acceleration directed downward
just before it reaches the peak of the path of its motion an object thrown upward has
its velocity directed upward and its acceleration directed downward
the fundamental unit of work and energy is
joule and joule
the SI unit most comparable in size to the US lbs unit is
kilograms
a squid pushes water back with its tentacles to allow it to swim forward
law of action and reaction (3rd law)
heros engine is being shown, there water is escaping a hanging bucket at both sides causing the bucket to turn counter clockwise
law of action and reaction (3rd law)
in this scenario, three glasses with varying colored liquids are holding a single cup with green liquid in it. the only thing between the cups are a paper plate. which law does this represent?
law of inertia (newtons first law)
two objects attract each other with a force that is proportional to the product of their masses, and inversely proportional to the distance between the objects
law of universal gravitation
when two lamps are connected in parallel to a battery, the electrical resistance that the battery senses is
less than the resistance of either lamp
with magnets
like poles repel one another
a unit of volume in the metric system is
liter
which of the following is not an appropriate unit for measuring acceleration
m/s - whatever doesnt have a squared at the end
a vector has
magnitude and direction
which of these never change even on different planets
mass
what is important to the development of scientific explanations
measurements, communication, and debate
which type of energy do I have to supply to an electricity generator? which type of energy do i get out of an electricity generator
mechanical, electrical
the material a wave travels through is called the
medium
why are metals useful for making electrical wire?
metals are conductors
the basic unit of length in the metric system is the
meter
the metric unit most comparable in size to the english inch unit is the
meter
the source of all magnetism is
moving electric charge
two skaters have just pushed off against one another. one skater has twice the mass as the other. which one will experience the greater momentum?
neither, they both have the same momentum
the law of universal gravitational is credited to whom
newton
a person walks out of a store with a pillow at the top of an overflowing shopping cart. while walking to the car, the carts wheel hits a large rock, causing the cart to suddenly stop. the pillow slides forward
newtons first law
you put your notebook on the front seat of your car. when your car stops, the notebook slides off forward, why?
no force is pushing it
in projectile motion with no air resistance, the horizontal component of the velocity at the top of the trajectory is
non zero, and equal to the initial horizontal component of the velocity
if these teams are pulling with the same amount of force what will happen
none of the teams will win
you stand on a scale that rests on the floor of an elevator that is accelerating upward. what is the relationship between the force due to gravity and the normal force exerted by the scale?
normal force > weight
when the velocity of an object does not change, what happens to its acceleration
nothing, it does not accelerate
a negative distance implies that an object is
on the negative side of the origin
a negative distance implies that an on object is
on the negative side of the origin
which circuit contains two or more branches for current to move through?
parallel circuit
what type of circuit is this
parallel, the picture shows multiple connections that all lead back to the battery
aurora borealis is due to
particles from the sun deflected by earth's magnetic field towards high latitudes
The centripetal acceleration on an object in uniform circular motion
points toward the center of the circle
lightning is caused by the build up of electrical charges in a cloud, also known as static electricity. in typical thunder cloud the bottom of the cloud is negatively charged. what is the sign of the excess charge on the ground
positive
assume the x-axis to be an east west line with the positive direction pointing east. a car is moving east with a speed of 30m/s. the driver realizes that he forgot something at home. she stops the car, and turns around, moving west with a speed of 30 m/s. under these assumptions, what is the velocity before and after turning around?
positive before, and negative after turning around
protons are
positively charged particles
if the wavelength of an electromagnetic wave is about the size of the three story building, what type of radiation is it
radio wave
speed is a
scalar quantity
in which type of circuits, the currents has only one loop to flow through
series circuit
compared to the amount of electric resistance in the filament of a lamp, the amount of resistance in the connecting wire
should be less
at night you get in your car to drive to the store. the car starts but none of the lights work. which of the following activities would not be considered part of the scientific method?
slam the hood down hard
which exposes you to more radiation: smoking a pack of cigs or receiving a basic chest xray
smoking
changing the positive direction in a reference frame to the opposite direction does not change the sign of which of the following quantities
speed
an object moving in uniform circular motion has a constant ______ but a changing _____
speed, velocity
assuming andromeda rotates at a uniform rate, which stars are moving the fastest?
stars closest to the center
which of the following types of friction keeps an object at rest?
static
the accumulation of excess electric charge on an object is called
static electricity
the motion of a falling object is commonly investigated with the aid of a
stroboscope
the term for the application of the basic laws of nature to produce practical devices for mankind
technology
a 10 pound iron ball and a 2 pound iron ball are dropped simultaneously from a height of 100 meters. in real life, which ball will reach the ground first.
the 10lb ball
which represents the acceleration of the ball?
the arrow pointing inward
a ball rolls in a straight line along the horizontal direction. using motion diagram, describe the velocity and acceleration of the ball for each of the following situations
the ball moves to the right at a constant speed
a book is sitting on a desktop. identify the reaction force of the weight of the book. note: weight is the force created by the earth on the book)
the force created by the book on the earth
low and high tides occur due to the following reasons
the gravitational pull from the solar system and the earth revolve around the sun
when you walk on the ground, your foot pushes against the ground and the ground pushes back on you. the force that makes you walk is exerted by
the ground
what is terminal velocity
the highest speed an object reaches because air resistance offsets gravity in the real world
around the earth there are regions where a high number of charged particles are trapped. these regions are called the Van Allen belts. what causes them?
the magnetic field of the sun
a bar magnet passes through a circular loop of wires as shown below
the magnetic field will create an electrical field, and the electrons in the copper will start moving around
an essential feature of a scientific theory is
the making of predictions that can be tested
how is the total energy conserved, when a ball is dropped from a height h above the ground, till the moment before it touches the ground?
the potential energy at height h is converted to translational kinetic energy, keeping the total energy constant
resistances connected in series all have
the same current
the resistances connected in parallel circuits all have
the same potential difference
if an astronaut takes an object to the moon the following is true
the weight will change but the mass will be the same
which is stronger, the earth's pull on the sun or the suns pull on the earth?
they are the same
NASA engineers tested potential astronauts by putting them in a human centrifuge basically a super powered version of those rides at the fair you found. because
they can test astronauts withstand acceleration by changing the speed of rotation which eventually change the centripetal acceleration of astronauts
a ping pong ball collides with a bowling ball. which experiences the greatest force
they experience the same force
current carrying wires must by insulated because it is dangerous for anyone to touch current carrying wires if they are not insulated
true
if the acceleration is zero, the velocity is constant
true
in the case of uniform accelerated motion, the graph of velocity versus time is a straight line
true
instantaneous speed is calculated by choosing a short time interval during which the speed is held constant or as nearly constant as is practicable
true
what happens when an xray beam is turned off?
turning an xray machine off leaves the area free of radiation
if a bar magnet is cut in half, the results will be
two bar magnets, each with north seeking pole on one end and a south seeking pole on the other
photons are
uncharged, particle like bundles of energy
the strength of the force of gravity between two objects depends on
universal gravitation constant, the mass fo the planet and the mass of the object, and the distance between the objects
what is the direction of the angular momentum vector for a wheel spinning as shown below
upward - counterclockwise
a rocket with a mass of 3000kg turns and fires its engine with a thrust of 300,000N. because of this thrust the rocket must be accelerating
upward at 100 m/s^2
velocity is a
vector quantity
the slope of the distance traveled versus time graph is the
velocity
the slope of the velocity versus time graph is the
velocity
the acceleration of a body is given by the slope of the graph of
velocity versus time
london millennium footbridge was designed to support up to 5000 people. when it first opened thousands crossed together and the bridge collapsed. the main reason for the collapsed is
vibrations which resulted in the bridge swaying sideways
in free fall, an object appears to experience no weight
weightlessness
can you charge an object without actually touching it with another charged object?
yes, this is an example of charging by induction
an ice skater glides across a frozen pond at a constant velocity. what is the net force acting on the skater
zero
in projectile motion the vertical component of the velocity at the top of the trajectory is
zero