Physics 102 Lab Final: Study Guide
If provided with a steel sewing needle, a known bar magnet, and a piece of thread, devise two methods to determine if an unknown steel rod is magnetic.
- Put needle next to magnet to see if it attracts - Attach needle to string, hold near a magnet
What do you expect when you convert minus 40 degrees Celsius to degrees in Fahrenheit?
-40 degrees Fahrenheit
Consider a mixture of water and sulfuric acid which has two electrodes in it. If the resistance of the mixture between the electrodes is 500 ohms, how much current must be sent through the water for a voltage of 10 V to exist across the electrode?
.02
What is the wavelength on the CRO of a 1000 Hz signal if the Time/div. is set at 1 ms/div.?
1 div
An object has a density of 2.0 g/cm^3. What is its observed mass in water if its mass is known to be 2.0 g?
1 g
How much will a 1.0 m copper wire expand if heated from 20 degrees to 30 degrees Celsius?
1.7 X 10^-4 m or 0.00017 m
A radioactive isotope of iodine has a half-life of 8 days. How much of an 80-kg sample of this isotope is still radioactive after 24 days?
10 kg
What is the lowest frequency the CRO can measure, assuming one complete wavelength must be present on the screen?
100 Hz
The temperature of a quantity of water was raised 20 degrees Celsius by 40 cal. of heat. Knowing the specific heat capacity of water, determine how many grams of water were heated.
2 g
What is the wavelength on the CRO of a signal with a period of 4.0 ms if the Time/div. is set at 1 ms/div.?
4 div
What is the voltage across a 10 k ohm resistor if a current of 5 mA is passed through it?
50 volts
If the Volts/div. is set at 0.1 V/div., what DC voltage would cause a shift width of 0.5 div.?
5v
If a radioactive isotope or substance has a decay constant of 0.01 sec^-1., what is its half-life?
69.3 Sec
What labs purpose is to gain insight regarding half-lives of radioactive isotopes by determining the half-life of a number of simulation blocks?
A Simulation of Radioactive Decay
Compared to an empty ship, will the same ship loaded with Styrofoam float higher, lower, or at the same level?
A ship loaded with Styrofoam would float lower than the same empty ship
How is a compass constructed?
A suspended magnetic needle that, dial and housing holds everything in place
An iceberg floats in salt water. Eight-ninths (8/9) of its volume is below water. Find A. How much of the iceberg is above the water. B. The density of the iceberg.
A. 1/9 B. .92 g/cm^3
An object weighs 15 N in water and 19 N out of water. Find A. The apparent weight of the object. B. The buoyant force acting on the object. C. The identity of the object if the density of the object is 11.3 g/cm^3. Refer to the substance table.
A. 15 B. 4 N C. Lead
An object is immersed in a fluid. State the relationship between the weight of the object and the buoyant force acting on the object if A. The object floats B. The object sinks C. The object neither floats nor sinks
A. The density of the object is less than the fluid B. The density of the object is more than the fluid C. The density of the fluid and object are equal
A baked potato is wrapped in aluminum foil and placed in a hot oven. After a while, which will be hotter: the potato or the foil? Why?
Aluminum because it's a better absorber of heat
A boat sails from fresh water to salt water. Will the boat float higher, lower, or at the same water level?
As the boat sailed from fresh to salt water, it would float higher
Explain why a beach towel feels cooler than the surrounding sand when both have received the same amount of solar heating.
Beach towels have a higher specific heat capacity than sand
Which expands most per unit of length when the temperature is increased: copper, steel, or brass? How do you know?
Brass, had the largest coefficient of linear expansion
Referring to the half-life table above, which substance is most likely to be used to date or find the age of organic materials?
Carbon^14
A bedroom floor is carpeted and a bathroom floor is ceramic tiled. If the rooms are connected and are at the same temperature, which floor has a higher specific heat capacity?
Carpet
The decay rate or activity of a radioactive substance is related to what?
Decay constant of the element
If glass expanded more than mercury, how would the temperature have to change for the column of mercury in a mercury thermometer to rise?
Decrease the temperature of the glass, to were the glass would be the same temperature as the mercury
What labs purpose is to determine the density of an object more dense than water and the density of an object less dense than water using Archimedes' Principle?
Density (Archimedes' Principle)
Who has higher electrical resistance, a person with dry skin or with wet skin?
Dry skin
Which expands more: a solid, a liquid, or a gas?
Gas
How would the graph of "A" versus t change if Lambda were decreased?
Get steeper
If the field lines are close together, does it mean the magnetic field is greater, or weaker?
Greater
If two resistors of equal value are placed in parallel, which is the total resistance?
Half of the resistor value
How would the decay constant change if 3 block faces were painted black?
Increase
Which will get hot faster in the Texas summer sun: water, iron, or wood? Why?
Iron because it has a lower specific heat capacity
What is a main condition for resistors in series?
It = I1 = I2 = . . .
Superconductors are materials which lose all electrical resistance when cooled to temperatures approaching absolute zero. If it were possible to apply a given voltage across such a material, what would the corresponding current be?
It approaches infinity
How does the temperature of boiling water change as heat is added?
It doesn't change
When an iron ring is heated, what happens to the sizeof the hole?
It expands outward
In a simple circuit if the voltage across the circuit stays constant, but the resistance doubles, what happens to the amount of current?
It half's, smaller
If you plug an electric toaster rated at 110 V into a 220 V outlet, how will the current in the toaster change?
It would double
If the resistance between two terminals were infinite, what could one conclude about the circuit?
It's an open circuit
When an aluminum sphere is heated, is its volume most likely or less likely to expand?
Its volume is most likely to expand
For a phase change from solid to liquid, which of the following is needed: latent heat of fusion or latent heat of vaporization?
Latent heat of fusion
Explain why a life jacket helps you float.
Life jackets help you float because it is less dense than water
What labs purpose is it to investigate the linear thermal expansion and determine the linear coefficient of expansion of a metal rod?
Linear thermal expansion
Desert sand is very hot in the day and very cold at night. Does sand have a high or low specific heat capacity?
Low
What labs purpose was to learn about magnets and magnetic fields?
Mapping Magnetic Fields
If the specific heat capacity of water were lower than it is, would ponds be more or less likely to freeze in winter?
More likely
Describe the motion, if any, of a compass needle if the compass is moved from the northern hemisphere to the southern hemisphere?
Needle will not change direction
Do all radioactive isotopes have the same half-life?
No
In this experiment, does phase change occur when the temperature increases from 0 degrees Celsius to 100 degrees Celsius?
No
Is there a possibility for the field lines to cross over each other?
No
Does the number of cubes thrown affect the length of that half-life?
No, it should not
If a bar magnet is cut in half, are the north pole and south pole isolated? Explain.
No, mono-pole exist in nature
Is it fair to say that the amount of heat needed to change ice to water is the same as the amount of heat needed to change water to steam? If not, which phase change requires more heat?
No, water to steam requires, more heat
Which pole of a compass needle points to a south pole of a magnet?
North Pole
Why do some objects sink in a fluid?
Objects that sink in a fluid have a higher density than the fluid they're in
Are the headlights of a vehicle connected in series or in parallel?
Parallel
In a string of Christmas tree lights, is it easier to find a burned light bulb when they are connected in series or in parallel?
Parallel
Two light bulbs are first connected in series and then connected in parallel. Which connection is brighter?
Parallel
Why can a person float in a swimming pool?
People float when their density is less than the buoyant force
What labs purpose is to observe the phase changes which occur in water when a water-ice mixtures heated to boiling?
Phase Changes in Water
Refer to procedure 6. Looking at the drawn lines, where are the lines most concentrated?
Poles of magnet
What labs purpose was to determine the resistance of several objects using Ohm's law?
Resistance and Ohm's Law
What labs purpose is to learn how resistances add when in series and when in parallel, and the relationship between voltage V, current I, and resistance R to power P?
Series and Parallel Circuits
What happens to a displayed sine-wave when the level knob <28> is pulled out?
Shifts it 90 degrees
It is known that resistance is directly proportional to the length of a conductor. For a given voltage, which allows more current to pass, a long or short lamp filament?
Short lamp
Which geographic pole of the earth is nearest the magnetic north pole of the earth?
South Pole
What labs purpose is to determine the specific heat capacity of a solid?
Specific Heat Capacity
Which would burn the most: water at a temperature of 100 degrees Celsius or steam at a temperature of 100 degrees Celsius? Why?
Steam has more energy and can become hotter
How did stirring of the water-ice mixture affect the results?
Stirring evens out the waters temperature. so the ice melts faster
Keeping in mind the linear expansion of steel, what time of year should one construct a barbed-wire fence to have the strongest fence all year long? Why?
Summer, because it would tighten in the winter rather than getting loose and falling apart
What labs purpose is to become acquanited with the uses and operation of a cathode ray oscilloscope?
The Oscilloscope
Why is the thermometer not allowed to touch sides of the breaker?
The beaker heats up at a different rate than the water
Why is there a gap (expansion joint) in bridges and railroad tracks?
The gaps allow for the materials of the bridges/tracks to expand from heat
Lobsters live on the bottom of the ocean. How does the density of the lobster compare with the surrounding sea water?
The lobster is denser than water
How would one expect the graph of temperature versus time to change if the temperature of the Bunsen burner flame were increased?
The temperature would go up faster, so the slope would be steeper
What would happen to the lower and higher points if this experiment was conducted on Mount Everest?
The temperatures would be lower
Refer to procedure 9. Which gains heat in the calorimeter: the metal ball or the water?
The water
What does a zero resistance between two terminals imply about their method of connection?
There is direct connection
What labs purpose is it to determine the lower and higher fixed points of a thermometer?
Thermometer
In how many ways can the amount of current be increased in a simple circuit?
Two
How could four 8 ohm speakers be connected to yield a total resistance of 8 ohm?
Two sets of parallels
Assuming there is a bar magnet inside of a soccer ball, how would you distinguish the north pole from the south pole?
Use a magnet to the ball, the same will diverge, while the opposite will attract
What does a complete and functional simple circuit consist of?
Voltage source, resisting material, electrical current
What is a main condition for resistors in parallel?
Vt= V1 = V2 = . . .
Which has the highest specific heat capacity: water, iron, or wood?
Water
Explain why it would be best to have your feet wet if you were to walk barefoot on hot coals without harming your feet?
Water builds a barrier between your feet and the coals so the water will evaporate before you get burned
Is the chance of light bulb burnout greater while it is operational, or when it is cool and then turned on?
When it is cool and then turned on
Do all forms of thermal expansion occur in a piece of metal such as iron?
Yes
Do you get the same result if you convert minus 40 degrees Fahrenheit to degrees in Celsius?
Yes
Does location where the experiment is conducted have any effect on the outcome?
Yes
Does pressure have any effect on this experiment?
Yes
Is radioactive decay a random process?
Yes
Refer to procedure 5. Does your experiment's result change if you fill the cup all the way instead of three-quarters?
Yes
Does the observed melting point of ice agree with the stated accepted value?
Yes, it is close @ 3.5 degrees Celsius
In general, do all states of matter expand? Why?
Yes, temperature makes molecules expand
Find the lower and higher fixed points of the thermometer in kelvin?
lowest: 253.15 K highest: 383.15 K
