- Questions about the lab exercises.
- Questions you missed on the last quiz.
- Questions on homework assignments.
- Questions similar to the ones we did in class.
We will probably not get to everything on this list. Check the assignments page (and come to class!) to find out what exactly what we have and have not covered.
- Explain in your own words the 'scientific attitude'.
- What is the difference between science and pseudo science? Give some examples.
- Why do we think astronomy is a correct way of viewing the universe but astrology is not?
- What is the difference between science and religion? Do the two conflict with each other or not? Explain.
- What is the difference between science and technology? Scientists are responsible for science, who is responsible for technology?
- Why are approximations useful in physics? (Aren't scientists always interested in exact answers?)
- If x and y represent physical quantities which have different units, which of the following operations are possible? a) x+y b) x-y c) xy d) x/y e) y/x
- If r is measured in m/s , s is measured in J = kg m2/s2, k in kg, L in m and p in s, which of the following equations at least could be true based on their units? a) Lp2 = s; b) L/p = r c) r2 k = s; d) pk3 = s/L; e) 1/r = p/L
- What is dimensional analysis, how is it useful?
- What is the difference between dimension and precision?
- What is the difference between precision and acuracy? (Check the lab manual appendix for this one.)
- What is the difference between dimension and unit?
- What is an Order-of-Magnitude calculation good for?
- If we multiply several numbers with differing precision, which one determines the precision of the answer?
- If the total force (sum of all forces acting in each direction) is zero on an object can it have a non zero velocity ? Give an example.
- According to Newton's second law, F = ma. Give an example where the forces on an object are not zero but the acceleration is zero.
- A car is traveling at a constant 60 mph. What is the net force acting on the car?
- A marble sinks through a jar of honey at constant velocity. What can you say about the friction force on the marble?
- A marble was stuck to a rotating turntable but suddenly comes loose. Where does the force come from that pushes the marble off the turntable?
- Whiplash results from an automobile accident in which the victim's car is struck violently from the rear. Explain why the head of the victim seems to be thrown backward in this situation. Is it really?
- Since the earth is turning at a great speed, why is it that if you jump up in the air you are not instantly slammed against the wall?
- You are going to use a pulley and a single rope to support a weight hung from the ceiling. There are two was to do this: 1) you and tie one end of the rope to the ceiling, string the rope through the pulley, attach the pulley to the object and then pull up on the rope or 2) you can attach the pulley to the ceiling and the rope to the object, run the rope through the pulley and pull down on the pulley. Which way is easier and why?
- Does a car speedometer measure speed or velocity? What is the difference?
- What is the difference between velocity and acceleration?
- If an object has an instantaneous velocity of zero, can it have a non zero acceleration? Give an example.
- Can a rapidly moving object have the same acceleration as a slowly moving one? Explain.
- A ball is thrown up into the air. What is its acceleration on the way up? On the way down? At the very top when it stops to turn around?
- If the acceleration is the same on the way up, the way down and the very top of the path of a ball thrown up into the air, how do the velocities compare at these points?
- At the end of its arc, the velocity of a pendulum is zero. Is its acceleration also zero at this point? Why or why not?
- Which takes longer to reach the ground; a ball dropped from the window of a moving car or one dropped from the same height of a stationary car? Explain.
- Draw a graph of a constant velocity line on a velocity vs time graph. What is the value of the velocity of the line you have drawn?
- Sketch a graph of the motion of an object with zero acceleration on a velocity versus time graph. (velocity vertical, time horizontal)
- What physical quantity is represented by the slope of a distance versus time graph?
- What physical quantity is represented by the slope of a velocity versus time graph?
- What is the difference between average velocity and instantaneous velocity?What is the difference between velocity and acceleration?Why is it useful to make a graph of data?
- What is the relationship between a graph of a straight line and the mathematical equation y=mx+b?
- What is the physical quantity given by the slope of a distance versus time graph?
- What is the physical quantity given by the slope of a velocity versus time graph?
- Why do objects experience the same acceleration due to gravity, regardless of their mass?
- Explain the difference between mass and weight.
- You are in space where objects appear to be weightless. Which is harder to accelerate, a baseball or a refrigerator (or does it make any difference since they are weightless)?
- If the acceleration of an object is zero, does it mean there are no forces acting on it or no net force? Explain the difference.
- Without air resistance a heavy skydiver would accelerate at the same rate that a light skydiver would so at any instant they would have the same speed. With air resistance, however, the heavy skydiver ends up with a higher thermal velocity than the light skydiver. Explain how this happens.
- If you lock the wheels on your car while coming to a stop and utilize kinetic rather than static friction, does your stopping distance increase or decrease? Explain.
- A big car and a small car collide. From Newton's third law we know the two cars will experience the same force. Which car experiences the bigger acceleration?
- A dropped rubber ball will bounce. Which of Newton's three laws explains where the force comes from which causes the ball to bounce back into the air?
- Why does a runner accelerate if Newton's third law is correct ? Isn't the net force zero in this case ?
- How can anything move if there are always two forces which are equal and opposite?
- A car going down the highway hits an smashes a bug. Which has the larger force on it, the bug or the car? (Careful!)
- If you hop off of a chair the earth's gravity pulls you down. Name the reaction force and what it acts on in this case.
- If you were to fall out of a third floor window, which would you rather land on, concrete or a hay stack? Explain why.
- If you throw and egg at a wall it will break but if you throw it at a sheet held up loosely by two people it does not. Why?
- How can a rocket work in space where there is nothing for the exhaust to push against?
- What is the difference between an elastic collision and an inelastic collision?
- Under what cases can you apply momentum conservation?Is momentum conserved when a ball of putty hits the floor? Explain.
- Momentum and kinetic energy both have mass and velocity in them. What, then, is the difference between conservation of momentum and conservation of energy?
- A big car and a small car collide and stick together. You now know that the force on each is the same but the acceleration of the small car is more than the acceleration of the big car. Which car has the biggest momentum change?
- An empty box slides across the frictionless surface of a frozen lake. Which principle of physics tells you that the box will slow down as water collects in it from a rain shower?
- Which principle of physics tells you that a rifle will recoil when a bullet is fired from it? (the answer is not Newton's third law)
- A ball dropped onto a hard surface will rebound. The momentum of the ball is clearly not conserved since it's change in momentum is 2mv if it rebounds with the same velocity. Does this contradict the law of conservation of momentum? Explain.
- Why does an inflated balloon fly across the room when released? (The answer is not Newton's third law.)
- Can an object have a center of mass located at a place where there is no mass?What is meant by elastic and inelastic collisions?
- Under what conditions is momentum conserved?Under what conditions is total mechanical energy conserved?
- Under what conditions is kinetic energy conserved?
- Why do we need both conservation of momentum and conservation of mechanical energy? Both have mass and velocity in them so what is the difference?
- Momentum is a vector and energy is not. How does this make conservation of momentum problems different than conservation of energy problems?
- Can gravitational potential energy be negative? Explain.
- Can kinetic energy be negative? Explain.
- A dog is pulling on his chain the other end of which is attached to a tree. Is the dog doing any work? Explain.
- Why is it easier to climb a mountain via a zigzag trail rather than climbing straight up?
- When a baseball is being thrown, is any work done on the ball while it is in contact with the pitchers hand? Explain.
- When a baseball is being thrown, is any work done on the ball after it has left the pitchers hand? Explain.
- We know the net force on a car moving at constant velocity is zero. We also know work is done by the motor. How can this be?
- What is efficiency?
- Gasoline engines are only about 30% efficient at best. Where does the rest of the energy go?
- Is it possible to build an engine or other device that puts out more energy than it consumes? Why not?
- Which of the following are always conserved? momentum, kinetic energy, total energy, work, potential energy
- Which of the following are conserved in an inelastic collision? momentum, kinetic energy, total energy, work, potential energy
- There is a book on your table. To measure its gravitational potential energy does it matter if you measure h from the floor of the room below us?
- What is the ultimate source of the energy found in fossil fuels?
- What is the difference between power and energy?
- Does the gravitational force of the earth do work on a moving satellite? Why or why not?
- Is kinetic energy a vector or not? How do you know?
- Is gravitational potential energy a vector or not? How do you know?
- What is the difference between work and power?
- Does an electric utility sell power or energy?
- Why do we need the dot product in the definition of work?
- It is possible to tell a hard boiled egg from a fresh egg by spinning it. Explain why the hard boiled egg spins but the the raw one will not.
- What is the difference between rotational inertia and angular momentum?
- Which would be easier to stop, a rotating bicycle tire filled with air or one filled with water? Explain.
- What is torque?
- During the spin dry cycle of a washing machine water leaves clothes as they spin at a high speed. What is the direction of the force acting on the clothes? What applies this force?
- During the spin dry cycle of a washing machine water leaves clothes as they spin at a high speed. The washing machine contains holes large enough to let water out but too small to allow the clothes out. Explain why the water separates from the clothes.
- Why does a spinning top not turn over?
- Draw a diagram of an object traveling in a circle and show the relative directions of centripetal force, centripetal acceleration, and tangential acceleration.
- Why does a football which spins on its axis not tumble after it is thrown?
- Communication satellites have antennae that must always point in the same direction. This can be accomplished by causing the satellite to spin. Why does this help and what principle in physics is used here?
- Why is it easier to loosen a bolt if you hold the end of the wrench rather than the middle?
- Explain how a child on a swing can cause the swing to rise higher and higher with out touching the ground by pumping his feet back and forth.
- During the spin dry cycle of a washing machine water leaves clothes as they spin at a high speed. The washing machine contains holes large enough to let water out but too small to allow the clothes out. Explain why the water separates from the clothes.
- What is moment of inertia?
- How is the cross product different from the dot product?
- Does the sun's gravitational force on the earth cause a torque on the earth? Why not? How do you know?
- How are angular momentum and linear momentum similar? Different?
- What are some examples where angular momentum is important?
- How do you determine the direction of the angular momentum vector?
- Why is it easier to balance a spinning basketball on your finger than a nonspinning one?
- Is it possible for objects moving in a straignt line to have angular momentum? Why or why not?
- What are some examples of conservation of angular momentum?
- A tennis ball traveling at 1m/s rolls off the edge of a horizontal table top. List the following at the instant it leaves the table: 1) y velocity, 2) x velocity, 3) x acceleration , 4) y acceleration.
- A hunter aims a gun directly at a monkey hanging from a limb. He points the gun directly at the monkey, failing to take into account gravity acting on the bullet. The monkey lets go and falls at the exact instant the bullet is fired. Will the monkey get hit or not ? Explain.
- Why do we need vectors in physics?
- What are Kepler's laws?
- Why are Newton's laws some how 'better' than Kepler's laws?
- What is a geo-sychronus orbit?
- Explain the first law of thermodynamics.
- Explain the second law of thermodynamics.
- Why can't you make a car that is 100% efficient?
- Why can you heat a room by opening the stove and turning it on but you can't cool a room by opening the refrigerator and leaving it on?
- What happens to the efficiency of a heat engine if the temperature of the cool reservoir is increased? Explain.
- Do organisms break the second law of thermodynamics when the grow up to become more ordered? Explain.
- What is the difference between heat and temperature in microscopic terms?
- What is the classical microscopic interpretation of absolute zero and why is it incorrect?
- How are pressure and temperature related on a microscopic level?
- What information does the Maxwell-Boltzman distribution tell you about a gas?
- How do you use the Maxwell-Boltzman distribution to find the average, most probable and the rms speeds?
- What are the microscopic interpretations of specific heat and latent heats?
- Explain the mechanisms of heat transfer (conduction, radiation, convection, evaporation) in microscopic terms?
- How does an atomic theory of matter explain evaporative cooling, thermal expansion, Brownian motion, change of phase, and surface tension?
- What is the difference between longitudinal and transverse waves?
- Explain the superposition principle for waves.
- Pitch in a sound wave corresponds to which numerical quantity?
- What quality does frequency tell you about for visible light?
- How are wavelength and frequency related?
- What is interference of waves? Give some examples.
- What is the Doppler effect? Give some examples of the use of the Doppler effect in every day life.
- What are sound waves?
- Why don't sound waves travel in a vacuum?
- Do radio waves travel in a vacuum? Light waves?
- If you hear the sound of thunder 3s after you see the lightening, about how far away is the storm?
- What is resonance?
- What are beats?
- How is an AM signal different from FM?
- What is the difference between radio waves and sound waves? How does Hooke's law figure in simple harmonic motion?
- What are some examples of simple harmonic motion?
- For the frequency of a mass on a spring in simple harmonic motion the length of the spring does not matter but the mass does but for a pendulum the length matters but the mass does not. Why is that?
- Suppose you have a Hooke's law force that looks like F = C ln(a) x/b where C, a and b are constants. What would the frequency be for harmonic motion due to this force?
- Under what circumstances do we expect that resonance might become a factor for a vibrating system?
- Suppose you have a system that will undergo resonance at a certain frequency. List several ways to prevent resonance for the system while still having it vibrate.