7 ideas that shook the universe
At point ③(just as he is hitting the bucket) his kinetic energy must be a. 10,000 J. b. 7,500 J. c. 5,000 J. d. 2,500 J
10,000 J
If the hammer weighs 250 N and a player lifted it 0.50 m off the table, he did _____ J of work. a. zero b. 125 c. 250 d. 500
125
In that same set of drawings, above, with which picture or pictures would Galileo agree? a. 1 only b. 2 only c. 3 only d. both 1 and 3 e. both 1 and 2
2 only
Suppose his gravitational potential energy at the top is 10,000 joules and at point ① (one quarter of the way down) it is 7,500 joules. Ignoring air friction, his kinetic energy at point ① is, therefore a. 10,000 J. b. 7,500 J. c. 5,000 J. d. 2,500 J. e. zero
2.500 J
Suppose the slider has 200 J of potential energy at the very top. What is the least amount of work a kid could give to the hammer to get the slider that high? a. 50 J b. 100 J c. 200 J d. 400 J
200 j
Use those same answer choices to describe how Galileo and Newton would explain why the ball stopped. a. The batter stopped pushing it. b. The earth's gravity pulled it down. c. The internal motion was exhausted. d. A friction force from the grass stopped it.
A friction force from the grass stopped it.
What is a 'law of nature'? a. A mathematical formula for predicting the results of experiments. b. A pattern that someone observes in the behavior of nature. c. A set of absolute facts that someone discovers. d. A mystery that we humans can never understand.
A pattern that someone observes in the behavior of nature.
One reason it was so hard to accept Copernicus' model was that it didn't work any better than the old model. What's another reason? a. The Catholic church hierarchy supported the old model. b. There was no scientific evidence that the earth moved. c. His model made the earth just another little planet, and not anything special. d. All of these!
All of these
The head of the Inquisition, Fr Maculano de Firenzuola, said in the film about Galileo that he was "too famous to burn." How did he get that way? a. By writing in Italian, rather than Latin, so everyone could read and appreciate him. b. By writing in an easy-to-read dialog style, rather than a long, scholarly essay. c. By becoming good friends with people in power, including Pope Urban VIII. d. All of these!
All of these
According to Galileo or Newton, how would they fall? a. The roll of quarters would fall much faster than the single quarter, because the roll is much heavier. b. The single quarter would fall much faster than the whole roll because it would feel much less air resistance. c. All the quarters would fall more or less side by side, cruising downward at a constant speed. d. All the quarters would fall more or less side by side, accelerating as they fell
All the quarters would fall more or less side by side, accelerating as they fell
In that same situation - with the cart rolling off on its own and coming to rest - why would Newton say that the cart stopped? a. The horse quit pulling it. b. The spirits of motion left it. c. An outside force of friction stopped it d. The cart's energy source was taken away.
An outside force of friction stopped it
Which of those four celestial objects - Antares, Jupiter, the Moon, and Venus - is by far the farthest from us? a. Antares b. Jupiter c. the Moon d. Venus
Antares
First proposed putting the sun in the center of the known universe
Aristarchus
Contrast the ways that Aristotle and Galileo would describe the motion of falling objects.
Aristotle - heavier things fall faster, fall rate depends on weight; Galileo - everything falls alike (Could add the Aristotle asserted that falling speed was constant, but Galileo said speed increases, or that objects accelerate as they fall.
How would Aristotle and Newton complete this sentence: Force ______ motion. a. Both would say that force causes motion. b. Aristotle would say that force causes motion, but Newton would that force changes it. c. Aristotle would say that force changes motion, but Newton would that force causes it. d. Both would say that force changes motion.
Aristotle would say that force changes motion, but Newton would that force causes it.
An apple would have to move sideways at 5 mi/sec to orbit the earth. Why? a. At that speed, centrifugal force just exactly balances the force of gravity. b. At that speed, the apple falls at the same rate as the earth curves under it. c. Apples don't weigh much; a person or a Space Shuttle would have to move faster.
At that speed, the apple falls at the same rate as the earth curves under it.
Scientists in Newton's time thought that objects, like apples and bricks, had gravity. Most people today think that gravity is in the earth itself. What do you think? a. The old scientists are actually right. b. Our modern view is more correct. c. Both are half right - gravity is between objects.
Both are half right - gravity is between objects.
Suppose your car slips off the road on a snowy day and hits one of those colored glass gazing balls that some people keep in their gardens. Which is true about the force between the car and the ball? a. The force of the car is much bigger, because the car is much more massive. b. The force of the car is bigger, because the car was moving and the ball was at rest. c. Both forces are exactly the same.
Both forces are exactly the same
Suppose you put a rubber band over your thumb and index finger and stretch it out. Which exerts the greater force, your thumb or your finger? a. My thumb. b. My index finger. c. Both just the same. d. It depends which one I use to pull the rubber band.
Both just the same
Speaking of the end of the universe - which of these ultimate fates seems most likely at this time? a. Continuous expansion and cooling of the universe - the 'Heat Death.' b. Continuing existence more or less as it is now, forever into the future - the 'Steady State.' c. Eventual contraction of the universe into a black hole - the 'Big Crunch.' d. Eventual contraction of the universe, with a rebound back into a new universe..
Continuous expansion and cooling of the universe - the 'Heat Death.
Water, with a high entropy, placed in your freezer becomes ice, with a low entropy. How can that be, in light of the second law?
Entropy can go down in the refrigerator, but only because it goes up even more in the power plant.
Suppose you could travel to the moon and drop a pen from arm's length. What would the pen do? a. Float in place where I let it go. b. Fall slowly to the moon's surface at a constant speed. c. Fall slowly to the moon's surface, accelerating as it falls. d. Fall just exactly as it would here on earth. e. Drift back toward the earth
Fall slowly to the moon's surface, accelerating as it falls.
How much kinetic energy does the hammer have if it is swung twice as fast? a. The same amount at all speeds. b. Twice as much if it's twice as fast. c. Four times as much if it's twice as fast.
Four times as much
Jupiter has 63 known moons orbiting it. The first four of those were discovered by a. Galileo. b. Kepler. c. Newton. d. Tycho.
Galileo
Why are heat engines inefficient, in general? a. Temperatures are so high that a great deal of heat is lost to the environment. b. We don't have many good heat sources to use. c. Heat engines attempt to convert the worst source of energy into the best. d. They are always complicated, and friction from all the moving parts wastes energy
Heat engines attempt to convert the worst source of energy into the best.
One of your classmates says that heat is the same as temperature, and another says that heat is the same as thermal energy. What would you say to clear up the confusion?
Heat is thermal energy on the move due to a difference in temperature. Temperature is the concentration of thermal energy.
What's wrong with saying "heat rises?"
Heated air rises, as in a building with a high ceiling, or a hot-air balloon. But heat itself goes to a colder place, no matter if it's up or down or sideways.
At a family get-together, your weird uncle (every family has at least one!) says that he knows a guy who heard about another guy who invented a carburetor that would make cars go ten times farther on a gallon of gas, but that big oil companies bought him out and won't let him sell it. As a physics student, what would you say to him?a. Uh-huh, that's interesting. Wow, you don't say! b. That would be great! We learned that heat engines are really inefficient, so we need a way to make them work better! c. I don't think that sounds right, because then the car would put out more energy than it takes in.
I don't think that sounds right, because then the car would put out more energy than it takes in.
Why was it important in the history of physics that Jupiter had moons orbiting around it? a. In the previous model every planet had only one moon. b. In the previous model everything orbited the earth. c. The Bible never mentioned moons orbiting other planets. d. It really was not all that important.
In the previous model everything orbited the earth.
How can you improve the efficiency of a heat engine?
Increase the difference in temperature - either make the hot side hotter, or the cold side colder. The warm of our natural environment makes it tough to do much with the latter.
Here is another cartoon from that same show. The larger arrow is the ground pushing forward on the horse, while the smaller one is the friction of the ground holding the cart back. What is happening to the cart at the moment pictured? a. It is moving forward at a constant speed. b. It is accelerating forward, picking up speed. c. It is slowing down. d. There's no way to know, from the drawing alone.
It is accelerating forward, picking up speed.
Absolute zero is sometimes described as the temperature where everything stops moving. What's a better definition?
It is the temperature from which energy can no longer be obtained or withdrawn, as heat can only flow from warmer to colder. Also, it is the one temperature which can never be attained or reached - the so-called Third Law in the text.
The PowerPoint show on Newton's laws included this cartoon from physics teacher and writer Paul Hewitt. What do you think about what the horse is saying? a. Oh my God! The horse is TALKING! (Don't pick this one.) b. It's true - if only the third law is considered, nothing could ever move. He'd have to think of the first and second laws, as well. c. It's true, but it's not the whole story. There are also forces on and from the ground that he is leaving out.
It's true, but it's not the whole story. There are also forces on and from the ground that he is leaving out.
First showed that planets move in elliptical orbits, and not circles
Johannes Kepler
In that model, what is about the same size as a pencil eraser? a. Jupiter. b. The earth. c. The moon. d. the next nearest star.
Jupiter
Which of these is a good description of orbiting? a. Motion where gravitational attraction is balanced by electrical repulsion. b. Motion where gravitational attraction is balanced by centrifugal force. c. Motion where an object is always falling, but goes so fast sideways that it always misses. d. The natural path of a speeding object.
Motion where an object is always falling, but goes so fast sideways that it always misses
Which if these is a deep meaning of Newton's First Law? a. Forces always come in pairs. b. Motion is a sacred or conserved quantity. c. Weight is not the same thing as mass. d. Moving uniformly feels the same as being at rest
Moving uniformly feels the same as being at rest
Again in that same model, how far away is the next star, past our sun? a. the MACC b. downtown Kent c. Cleveland d. New Orleans
New Orleans
Re-discovered the heliocentric or sun-centered model
Nicholas Copernicus
In question 3, what would we find in almost all of the space between our sun and the next nearest star? a. One planet after another. b. Lots of gas and dust that have not yet formed into stars. c. All the unmatched socks from our clothes dryers? d. Nothing - just a few molecules here and there.
Nothing - just a few molecules here and there.
What's the problem with all perpetual motion schemes?
One is friction! Sure, you can change one form of energy into another over and over, but a little but will always be lost. And another stems from the second law; as you change from one form to another, the quality of energy decreases, so if you change back to the original form in a closed cycle, you must have lost some energy along the way to get back to a higher quality form.
What's wrong with saying that one kilogram equals 2.2 pounds? a. Nothing - that is correct. b. It's close - one kilogram equals 2.25 pounds. c. One is a metric unit, and one is a British unit. d. One measures mass, and one measures weight
One measures mass, and one measures weight
Suppose a planet orbiting around some distant star has an orbit so elliptical that it is twice as far from the star at its far point (B) than it is at its near point (A). How does the force between the star and the planet at point B compare with the force between the star and the planet at point A? a. Four times the force at B than at A. b. Twice the force at B than at A. c. The same force at each point. d. Half the force at B than at A. e. One-quarter the force at B than at A.
One-quarter the force at B than at A.
Made the best geocentric or earth-centered model ever
Ptolemy
Which of Kepler's laws predicts that the earth moves faster through space in our wintertime than it does in the summer? a. First b. Second c. Third d. Actually, none of Kepler's laws do that
Second
List several ways to state the second law of thermodynamics.
So many! The quality of energy is always decreasing, entropy is always increasing, heat flows from hot to cold, no heat engine can be totally efficient, time moves forward, the universe is winding down...
Does the moon pull back on the earth? a. No, because if it did, the earth would have to orbit it. b. Sure, with the same force that the earth pulls on it. c. Sure, but with a smaller force, since the moon is so much smaller than the earth. d. Sure, but with a force so tiny that it doesn't matter at all.
Sure, with the same force that the earth pulls on it
Using that same apparatus, how much heavier would the ball on the right have to be for them to hit the base at the same time, according to Galileo? a. Half as heavy as the ball on the left. b. The same weight as the ball on the left. c. Twice as heavy as the ball on the left. d. That could not happen, no matter how heavy they are.
That could not happen, no matter how heavy they are.
What is the first law of thermodynamics?
The Law of Conservation of Energy, that energy can't be created or destroyed, but only changed in form
As a bird flies, its wings push down on the air. What is the reaction to that force? a. The bird flies forward. b. The air moves down away from the wings. c. The air pushes up on the wings. d. Some feathers may become loose and fall off.
The air pushes up on the wings
In that same dialog, Galileo proves that all objects fall alike. Yet when Sagredo dropped a huge cannonball and a much lighter musket ball, the cannonball hit the ground first. Why? a. Heavier things fall faster. b. The cannonball was able to plow through the air and was affected less by air resistance. c. Sagredo's measuring equipment was not accurate enough to determine which hit first. d. Galileo could not explain why there was a difference
The cannonball was able to plow through the air and was affected less by air resistance
How does the force on the bullet compare with the force on the gun at the moment the gun is fired? a. The force on the bullet is much greater. b. The force on the gun is much greater. c. The forces are exactly the same.
The forces are exactly the same
What is science? a. The fusion of observation and imagination. b. A precise method for systematically finding truth. c. The result of pure genius in the lives of a few famous men. d. A dangerous system of thought that has outlived its usefulness.
The fusion of observation and imagination.
Imagine that after the horse got the cart moving, the yoke connecting the cart and the horse broke, so that the cart was rolling on its own. Very soon it would come to rest. Why would Aristotle and the old-school philosophers say that the cart stopped? a. The horse quit pulling it. b. The spirits of motion left it. c. An outside force of friction stopped it d. The cart's energy source was taken away
The horse quit pulling it
Here is a finger-boiler pen. You touch your finger to the lower ball and the blue liquid inside boils up into the upper ball. As a good deed you send a crate of these to school kids in Iraq. During the long trip, some of the liquid sloshes into the top ball so that there is some in each. The kids open your gift on a very hot day when the air temperature is about 110 °F. What happens when a kid touches the lower ball? a. It works as usual - physics applies in every country. b. It works even better, because of the high temperature. c. The liquid moves down into the lower ball. d. Nothing happens at all. e. It explodes and leads to ANOTHER incident?
The liquid moves down into the lower ball
How does heat or thermal energy compare with all other forms of energy?
The lowest, most disorganized, least useful form of all - and therefore, the form to which all other forms will eventually go.
The earth pulls on the moon with a large gravitational force. Why doesn't that force make the moon come crashing down into us? (Or maybe I shouldn't tempt fate with such a question!) a. The force is too weak at that distance to have any real effect on the moon. b. Centrifugal force from the moon's motion balances out the gravitational force. c. Gravitational forces from the other planets hold it up. d. The moon is falling toward us but moves so fast sideways that it always misses.
The moon is falling toward us but moves so fast sideways that it always misses.
In class I dropped a red ball and a blue ball, each the same size and mass, from the same height above the table. The red one bounced back nearly to the same height from which I dropped it, but the blue one barely bounced at all. If I were to drop them many times, right after the other, what would you notice about their temperature? a. Both would have the same temperature, of course. b. The bouncy red ball would be warmer. c. The not-so-bouncy blue ball would be warmer.
The not-so-bouncy blue ball would be warmer.
Suppose you could drop one quarter and a roll of quarters from arm's length above a table at the same time. According to Aristotle, how would they fall? a. The roll of quarters would fall much faster than the single quarter, because the roll is much heavier. b. The single quarter would fall much faster than the whole roll because it would feel much less air resistance. c. All the quarters would fall more or less side by side, cruising downward at a constant speed. d. All the quarters would fall more or less side by side, accelerating as they fell.
The roll of quarters would fall much faster than the single quarter, because the roll is much heavier
7) How hard does the spring push on each cart? a. Twice the force on the more massive cart. b. Twice the force on the less massive cart. c. The same on each cart.
The same of each cart
If you spin a bucket of water in a vertical circle up over your head, why don't you get wet? a. Centrifugal force holds the water up. b. Centrifugal force cancels the force of gravity. c. The water is moving so fast sideways that it doesn't have time to fall. Do NOT pick a or b!
The water is moving so fast sideways that it doesn't have time to fall.
Why do astronauts orbit the earth about 200 miles above the surface? a. There is no gravity at that altitude, as shown by the fact that the astronauts float in their ship. b. There is no air at that altitude, so they can fly fast enough without friction. c. They are high enough to see the entire earth's surface at that height. d. That's as high as our rocket boosters are able to lift them.
There is no air at that altitude, so they can fly fast enough without friction
You have grown from a tiny cluster of identical cells to the magnificent creature that you are now, and in the process entropy has decreased in your own body. How is that possible, in light of the Second Law of Thermodynamics? a. The law only applies to machines, and not to living systems. b. The law only applies to the universe as a whole, and not to the separate parts in it. c. There is no problem, as the Second Law says that entropy always decreases. d. There is no problem, as entropy has gone up a great deal in all the food you have eaten
There is no problem, as entropy has gone up a great deal in all the food you have eaten
Which of Kepler's laws applies to all planets in the same way, unifying them into one solar system? a. First b. Second c. Third d. Actually, none of Kepler's laws do that.
Third
The middle of the Lion section is three times higher than the middle of the Bear section. How much more gravitational potential energy does the slider have at the Lion than the Bear? a. Twice as much. b. Three times as much. c. Four times as much. d. Nine times as much.
Three times as much
Why did Galileo study falling motion using pendulums and inclined ramps?
To slow down the effects of gravity, to 'dilute' gravity so that motion could be measured more easily.
Here's a sketch of an apparatus that neither Aristotle nor Galileo could have imagined. The two cylinders are electromagnets which drop steel balls at exactly the same time, but from two different heights. The ball on the right is dropped from twice the height as the ball on the left. How much heavier would the ball on the right have to be for them to hit the base at the same time, according to Aristotle? a. Half as heavy as the ball on the left. b. The same weight as the ball on the left. c. Twice as heavy as the ball on the left. d. That could not happen, no matter how heavy they are.
Twice as heavy as the ball on the left.
Made the most precise observations of planetary positions in his day
Tycho Brahe
According to the second law, how will the universe end?
Uniform, tepid boredom - the Heat Death where all sources of energy have eventually gone to thermal energy, and nothing else can happen. Bummer! But even if that's where we're going, it's billions and billions of years away.
Which of these could the game manufacturer do to make it hard to win the game? a. Oil the center pole so the slider moves freely. b. Use a light-weight slider. c. Use a shock-absorbing connector in the lever that moves the slider. d. Use a long-handled hammer.
Use a shock-absorbing connector in the lever that moves the slider
How would Aristotle and the Scholastics solve a scientific problem? a. Use their powers of intellect to think through the answer, by starting from known authorities. b. Ask other scholars what they thought, and come to an agreement by democratic principles. c. Find the answer themselves by carefully controlled laboratory experiments. d. One word - Google!
Use their powers of intellect to think through the answer, by starting from known authorities.
What causes Venus to appear to move backward, in that way? a. Venus is carried backwards by the movement of its epicycle. b. Venus actually stops moving in its orbit and changes direction. c. Venus' orbit is highly elliptical, so it seems to move in an unusual way. d. Venus only appears to move backwards; it's an optical illusion. e. I don't know about Venus, but I'll tell you about Serena...
Venus only appears to move backwards; it's an optical illusion.
Why was it so hard to prove that the earth is moving around the sun? a. It is not moving very fast, and we only feel rapid motion. b. We don't feel motion, but only changes in motion. c. People had believed for centuries that the earth did not move. d. No one had any reason to believe that the earth was moving.
We don't feel motion, but only changes in motion.
Right now the earth is pulling on you with a force we call your weight. How hard are you pulling back on the earth? a. Not at all - only the earth has gravity. b. With much less force than the earth pulls on me, since I am so small compared with the earth. c. With the same force that the earth pulls on me. d. I'm not pulling on the earth, but pushing against it through my chair.
With the same force that the earth pulls on me.
What is energy?
ability to cause change, or to do work, or to cause damage
How much work must the water in the bucket do to stop him? (Good luck with that!) The same as a. his kinetic energy just as he hits the water. b. his potential energy at the top. c. total energy at any point. d. all of these!
all of these
The Second Law also has to do with a. entropy. b. the direction of heat flow. c. the direction or nature of time. d. the ultimate end of the universe. e. all of these.
all of these
In this sketch, we have three different scenarios of two rocks dropped from rest at the same time. Let's say that the larger one is much heavier than the smaller one. In the first case, the two rocks are released side by side. In the other two, they are tied together by a large rubber band. With which picture or pictures would Aristotle and his followers, the Scholastics, agree? a. 1 only b. 2 only c. 3 only d. both 1 and 3 e. both 1 and 2
both 1 and 3
Here's a photo from the PowerPoint show about that scale model of the solar system. What would the tiny ball points on the tips of these two pens represent? a. Our sun and the next nearest star and the space between them. b. The position of the earth in January and July, so the space between them is the diameter of the earth's orbit. L c. The earth and the moon and the space between them. d. The earth and Venus and the space between them.
c. The earth and the moon and the space between them.
Complete this sentence as if you were Aristotle or one of the Scholastic thinkers of Galileo's time: Force _____ motion. a. causes b. changes c. is unrelated to
causes
) Now complete that same sentence as if you were Newton: Force _____ motion. a. causes b. changes c. is unrelated to
changes
Now complete that same sentence as if you were Newton: Force _____ motion. a. causes b. changes c. is unrelated to
changes
A black hole, the strangest thing in the universe, occurs when a star completely collapses in on itself. All of the mass is still there, just at one tiny point. What would happen to a planet in orbit around a star if the star suddenly collapsed into a black hole? The planet would a. escape and fly away in a straight line. b. continue to orbit just as it did before. c. get drawn into the black hole and be destroyed. d. Wait! We never studied black holes! This isn't fair! This question sucks! A black hole has intense gravitation up close, but at a distance its pull is exactly the same as the star before it collapsed. The star's mass is not going away, it's just getting very, very concentrated.
continue to orbit just as it did before
What was Halley's role in developing Newton's laws? He a. tricked Newton into getting back to work on them. b. helped with some of the calculations. c. paid for the whole project. d. did all of these.
did all of these
Which of these is true about gravitation, according to Newton? It a. affects all matter. b. reaches everywhere. c. always attracts. d. does all of these.
does all of these
What can you say about his energy at point ②, halfway down? a. four times as much potential as kinetic energy b. equal amounts of potential and kinetic energy c. four time as much kinetic than potential energy
equal amounts of potential and kinetic energy
Newton's Laws are taught so often and so early in school that most everybody knows something about them, enough so that they can be used in newspaper comic strips. Which of Newton's Laws is the basis of this cartoon? a. first b. second c. third
first
How fast do astronauts have to travel to orbit the earth? About a. three miles a second. b. five miles a second. c. seven miles a second. d. - there is no one answer; any speed will do.
five miles a second
And how fall in total will you have fallen after two heartbeats? a. two meters b. three meters c. four meters d. five meters
four meters
Now, in that same situation, what total distance do you fall after the first two heartbeats? a. one more meter b. two meters c. three meters d. four meters
four meters
Say you can stop your car in a certain distance at a certain speed. If you are traveling twice as fast, how far will your car move?
four times as far (not: twice as far)
What effect did Ptolemy's model have on the advance of astronomy? It was so a. good that it immediately led to greater and greater insights. b. good that it blocked the further advance of astronomy for 1500 years. c. much in error that other scientists quickly moved to correct it. d. much in error that other scientists ignored it and quickly changed to a better model.
good that it blocked the further advance of astronomy for 1500 years.
In what ways is Newton's law of gravitation universal?
gravitation affects everything, and reaches everywhere
In physics, what does mass really measure? How a. much of something that you have. b. much something weighs. c. hard it is to move something. d. much space something takes up.
hard it is to move something
Suppose you hold a bag of 13 potatoes in one hand and one single potato in the other, at the same height above a table, and let go of both at the same time. What would Aristotle predict should happen? When the bag of potatoes hits the table, the one lone potato would a. have fallen only one-thirteenth as far, with all the potatoes traveling at constant speeds. b. have fallen halfway down, with all the potatoes falling at constant speeds. c. hit the table at about the same time, with all the potatoes falling at constant speeds. d. hit the table at about the same time, with all the potatoes speeding up as they fell.
have fallen only one-thirteenth as far, with all the potatoes traveling at constant speeds.
In that same situation, Galileo would predict that when the bag of potatoes hits the table, the one lone potato would a. have fallen only one-thirteenth as far, with all the potatoes traveling at constant speeds. b. have fallen halfway down, with all the potatoes falling at constant speeds. c. hit the table at about the same time, with all the potatoes falling at constant speeds. d. hit the table at about the same time, with all the potatoes speeding up as they fell.
hit the table at about the same time, with all the potatoes speeding up as they fell.
Which of these is not an example of heat engine? a. home furnace b. electric power plant c. car or truck engine d. the earth's climate system
home furnance
What does it mean to say that energy is conserved?
it can't be made or destroyed
Why is the concept of work important?
it is the most organized or highest quality form of energy
Describe the energy changes which take place as a kid moves back and forth on a swing.
kinetic to potential to kinetic...
You remember that Kepler's Second Law says that a planet moves faster when closer to the sun. You can explain that by saying that when the planet is closer to the sun (compared to when it is farther away) it has a. less potential energy and more kinetic energy. b. less potential energy and less kinetic energy. c. more potential energy and less kinetic energy. d. more potential energy and more kinetic energy
less potential energy and more kinetic energy.
According to Newton's second law, how does acceleration depend on the applied force? How does it depend on the object's mass?
more force, more acceleration, or directly proportional; more mass, less acceleration, or inversely proportional
How much work is done when an athlete doing warm-ups pushes against a wall with a force of 100 N?
none at all (since the wall does not move)
According to Newton's law of gravitation, how does the gravitation force between two planets change if the distance between the planets doubles? if it triples?
one-fourth as great; one-ninth as great
In that model, our solar system would fit most neatly in a. our classroom. b. this building. c. our campus. d. Portage County. e. Ohio.
our campus
and the Second Law of Thermodynamics has to do with the _______ of energy. a. quality b. quantity c. form d. flow
quality
The First Law of Thermodynamics has to do with the _______ of energy... a. quality b. quantity c. form d. flow
quantity
Aristotle - and anyone else before Newton - would have said that the natural state of any object is a. rest. b. motion in a circle. c. motion in a straight line.
rest
Venus and Jupiter appeared to come so close together because Venus is moving 'backward' among the stars at this time, opposite the normal motion of the planets relative to the stars. That 'backward' motion is called a. accelerated motion b. orbital motion c. retrograde motion d. uniform motion
retrograde motion
Ignoring friction, how does the work needed to bring a car up to some speed compare with the kinetic energy it has at that speed? How does the kinetic energy at that speed compare with the work needed to stop it?
same;same
Sagan said that Copernicus' model worked "at least as well" as Ptolemy's. Why wasn't it any better? Because Copernicus a. still believed that all planets followed circular orbits. b. had the wrong spacing between the planets. c. had the earth in the center, with the sun and planets orbiting around it. d. did not allow for any moons around any of the planets.
still believed that all planets followed circular orbits.
Newton showed that the natural path for any speeding object is a a. circle. b. ellipse. c. straight line. d. none of these; the natural state is rest.
straight line
Which has more kinetic energy, an 800 kg Mini traveling at 20 m/sec or a 1600 kg Grand Marquis traveling at 10 m/sec? Or are they the same?
the Mini, because the speed is squared. For each, KE = ½ mv2
What is the reaction force to the force of a baseball bat hitting a ball?
the ball hitting the bat
A long fly ball in the baseball playoffs gets by the outfielder and rolls to rest in the grass. Aristotle and the Scholastics (a wonderful name for a 50's doo-wop group!) would say that the ball stopped because a. the batter stopped pushing it. b. the earth's gravity pulled it down. c. the internal motion was exhausted. d. a friction force from the grass stopped it.
the batter stopped pushing it.
Venus and Jupiter came into very close alignment in February, 2008, as seen from here on Earth. Also in that same part of the sky were the moon and the great supergiant star Antares. 6) If you compared this map with a sky map for the same time of day on the next day, February 2, which object would have changed its position the most - that is, which object moves most differently from the others? a. Antares b. the moon c. Jupiter d. Venus
the moon
Why do astronauts orbit the earth about 100 to 200 miles above the surface? Because a. there's no air up there to interfere with their motion. b. that's just beyond the reach of the earth's gravity, so they can orbit there. c. that's the height needed to photograph the whole earth at once. d. that's as far as they can go with the engine technology we have.
there's no air up there to interfere with their motion
Which feels the greater force as he stretches the rubber band, the guy's a. right thumb. b. left index finger. c. - they both feel the same force.
they both feel the same force.
You're going skydiving for the first time! You look out the door of the plane, and there is nothing underneath you to hold you up! Your heart is pounding so hard you can feel it - and you step out! If you fall one meter during the first heartbeat, how far will you fall during the next beat? (Not the total distance, but how far during that next heartbeat.) a. one more meter b. two meters c. three meters d. four meters
three meters
You're going skydiving for the first time! You look out the door of the plane, and there is nothing underneath you to hold you up! Your heart is pounding so hard you can feel it - and you step out! If you fall one meter during the first heartbeat, how far will you fall during the second beat? (Not the total distance, but how far during that next heartbeat?) a. one more meter b. two meters c. three meters d. four meters
three meters
You are going skydiving for the first time! Your heart is racing so from the excitement that you fall only one meter during the first heartbeat. How far will you fall during the second heartbeat? a. one more meter b. two more meters c. three more meters d. four more meters
three more meters
Suppose you drive to the top of one hill, then down into a valley and up a second hill that is twice as high as the first. How many times greater is your car's gravitational potential energy on the second hill than the first?
twice as much (not: four times as much)
Why doesn't the earth fall into sun? Because a. the sun's gravitation is too weak at this distance to affect the earth's motion. b. centrifugal force from the earth's motion balances out the sun's gravitation. c. gravitation from the other planets holds us up. d. we are moving so fast sideways that we always miss, even though we are falling!
we are moving so fast sideways that we always miss, even though we are falling!
Why was it so hard (and still is hard today) to demonstrate that the earth is moving? Because a. we always live on the earth, so we don't know what it would be like not to move. b. the earth is so large that it's difficult to measure. c. everything else on the earth is moving with us. d. we can't feel motion, only changes in motion.
we can't feel motion, only changes in motion.
Why is it so hard to prove that the earth is moving? Because a. we always live on it, and so are used to its motion. b. we always live on it, and so it's hard to have a reference point to measure from. c. we don't feel motion, only changes in motion, and the earth's motion changes gradually. d. it isn't moving very fast.
we don't feel motion, only changes in motion, and the earth's motion changes gradually
According to the Scholastics, what is it about the body, or object, that fixes its velocity, that is, that pre-determines how fast it will fall? Its a. shape. b. size. c. weight. d. air resistance.
weight
Does your car use more gasoline if the headlights are turned on?
yes
If I play my radio while I drive, do I affect my gas mileage? a. Yes, because the kind of music you play could affect your driving habits. b. Yes, because sound is a form of energy. c. No, because the radio runs off the car battery.
yes, because sound is a form of energy
What is the reaction force to the force of gravity from the earth on your body right now? Be careful!
your (or my) body pulling up on the earth (not: my body pushing on the earth)
Suppose a little kid tries to lift the hammer with a force of 125 N, but since it weighs 250 N, he can't budge it. How much work does he do? a. zero b. 125 J c. 250 J d. 500 J
zero
