Newton’s 2nd Law experiment using an inclined plane Purpose This lab experiment is to verify Newton’s second law and in the process also obtain the coefficient of kinetic friction between a block and an incline. Theory Newton’s 2nd law states that the net external force on an object in a given direction is equal to the mass of the object multiplied by its acceleration, Fnet = ma, where m is the mass of the object and a is its acceleration. Applying Newton’s 2nd law to the two objects as shown in the figure below, we obtain: m1g – T = m1a (1) T – m2gSin – fk = m2a (2) where fk = kFn (3) and Fn = m2gCos (4) from (2),(3), and (4) T = m2a + m2gSin + km2gCos (5) From (5), and for  = 0, T = m2a + km2g (6) Following equation (5), a graph of T vs. a should give a straight line where the slope will be equal to m2, and the coefficient of kinetic friction may be obtained from the intercept, since the intercept will be equal to (m2gSin + km2gCos) Procedure Open the simulation at https://ophysics.com/f3.html a. Choose a constant value for mass m2. b. Choose a value for  c. Choose a coefficient of friction low enough for the masses to move, and keep this coefficient constant. Verifying the acceleration d. Choose a value for m1 e. Using the “run” and “pause” buttons, run and pause make a table of at least seven data sets of h (take the absolute value) and time. f. Make a graph of h vs. time, and an appropriate curve fit to obtain the acceleration from your graph. (Hint: x = vit + ½ at2) g. Compare the acceleration from your graph with that provided by the simulation. Verifying Newton’s 2nd Law h. Vary m1, and record the corresponding acceleration, a, and tension, T, for several (at least seven) values of m1. i. Create a table for T vs. a j. Make a graph of T vs. a k. Choose an appropriate curve fit to obtain m2 and k from your graph (Hint: Equation 5) l. Compare the m2 and k from your graph to the actual m2 and k m. Repeat steps g to k using  = 0 (Hint: equation 6) n. Compare the two k values obtained from j and k. (do a percent difference) Questions 1. If a constant nonzero force is applied to an object, what can you say about the velocity and acceleration of the object? 2. Why can we neglect forces such as those holding a body together when we apply Newton’s second law of motion? Sources: 1. CCSU Physics Lab Manual 2. Ophysics.com 3. OpenStax College Physics

Experiment 1: Gravimetric Analysis with Calcium Chloride and Potassium Carbonate
In this experiment, proper analytical experimental techniques will be utilized to perform a double displacement reaction. A solution will be prepared containing a known quantity of calcium chloride. Then, the mass of calcium present will be determined through a careful precipitation of calcium carbonate. You will also investigate the hygroscopic nature of calcium chloride through a comparison reaction.
Materials:
Scale250 mL Beaker50 mL BeakerStir rod4.0 g Calcium chloride, CaCl25.0 g Potassium carbonate, K2CO3100 mL Graduated CylinderPipetteRing for ring standRing stand

Funnel250 mL Erlenmeyer flask2 Filter papersWatch glassWeigh boat*170 mL Distilled water*10 mL Isopropyl alcohol
*You must provide



Procedure
Place the weigh boat on the scale and determine its mass.
Add approximately 2.0 g of CaC to the weigh boat (the total mass should be     the mass of the weigh boat plus 2.0 g). Set this sample aside, and let it sit exposed to the air (but otherwise undisturbed) for 24 hours. Complete Steps 3 - 20 while you wait..
Place a 250 mL beaker on the scale. Tare the scale and leave the beaker on the scale..
Add approximately 2.0 g. of CaCl2 to the beaker. Record the exact mass of the powder in Table 1.
Remove the beaker from the scale. Use a pipette to add 50 mL of distilled water to the beaker and mix with the stir rod until all CaCl2 has dissolved.
             Note: This is an exothermic process, so the beaker may become warm.
Place a 50 mL beaker on the scale. Tare the scale and leave the beaker on the scale.
Add 2.5 g of K2CO3. Record the exact mass of the powder in Table 1.
Remove the beaker from the scale. Use a pipette to add 25 mL of distilled water   to the 50 mL beaker and mix with the stir rod until all K2CO3 has dissolved.
Add all of the K2CO3 solution to the beaker containing the CaCl2 solution. It is important that all of the K2CO3 is added. To ensure this, rinse the 50 mL beaker with up to 5 mL distilled water, and pour the rinse in the CaCl2 solution.
Stir the solution for approximately four minutes. Then, allow it to sit for 15 minutes. This gives sufficient time for all CaCO3 to precipitate.
While the solution is sitting, set up the filtration apparatus. Begin with an iron ring and a ring stand. Secure the ring to the stand. Be sure to select the ring size that most appropriately holds the funnel.
Place a funnel in the ring, and place a 250 mL Erlenmeyer flask below the ring, such that the bottom of the funnel is also inside the mouth of the flask.
Obtain a piece of filter paper. Use the scale to weigh the filter paper and record the mass in Table 1.
Obtain a watch glass. Use the scale to weigh the watch glass and record the mass in Table 1.
Fold the filter paper in half and in half again, so that it resembles a triangle with one arced side.
Pull apart one fold of the filter paper so that three sides of the filter paper remain together, with one side making up the other half of the funnel shape.
Place the paper into the funnel and seat with a small amount of distilled water (this will prevent the filter paper from rising up).
Filter the solution from the beaker (that you created in Step 9) slowly. Additional distilled water may also be used to transfer any remaining solid into the filtration apparatus.


After all the solution has been filtered, use the pipette to rinse the filter paper with approximately 5 mL of isopropyl alcohol to aid the drying process. Allow the isopropyl alcohol to completely drip through the filter before removing filter paper from the funnel.
Carefully remove the filter paper, unfold and place it precipitate-side up onto the pre-weighed watch glass. Be sure not to lose any product during this transfer.
Repeat Steps 3 - 20 for the CaCl2 that was allowed to sit exposed to air for 24 hours.
Allow the products from both trials to dry, undisturbed, for at least 24 hours and determine the mass of the product recovered by re-weighing the system and subtracting the weight of the filter paper and watch glass. Record your data in Table 1.

Table 1: Data and Observations
Substance
Trial 1
Trial 2
Mass of CaCl2:
 
 
Mass of K2CO3:
 
 
Mass of Filter Paper


Mass of Watch Glass


Mass of Product


Amount of Time Beaker Solution Stirred:


Amount of Time Beaker Solution Set:


Experimental Observations:







Calculations

First Trial

Theoretical yield (CaCO3):

Actual yield (CaCO3):

Percent yield:

Moles of Ca present in original solution, based on actual yield:

Mass of CaCl2 present in original solution, based on actual yield:
Second Trial

Theoretical yield (CaCO3):

Actual yield (CaCO3):

Percent yield:

Moles of Ca present in original solution, based on actual yield:

Mass of CaCl2 present in original solution, based on actual yield

Volume-Volume percent:

10 mL ice cold 4 % acetic acid in 95 % ethanol (v/v)

1. how many mL of acetic acid and how many mL of ethanol is needed to make 10 mL mixture of the two

Planned Parenthood of S.E. Pa. v. Casey case

Planned Parenthood of S.E. Pa. v. Casey

112S.Ct.2791 (1992)

[This decision upheld the Supreme Court's 1973 decision in Roe v. Wade, upheld numerous provisions of a Pennsylvania law restricting abortions, and invalidated a portion of that law. The following excerpt—a portion of the opinion of the Court announced by Justices 0 'Connor, Kennedy, and Souter—is provided/or its insights into the concept of stare decisis. The remainder of the case is presented in Chapter 12.]

The examination of the conditions justifying the repudiation of Adkins by West Coast Hotel and Plessy by Brown is enough to suggest the terrible price that would have been paid if the Court had not overruled as it did. In the present case, however, as our analysis to this point makes clear, the terrible price would be paid for overruling. Our analysis would not be complete, however, without explaining why overruling Roe's central holding would not only reach an unjustifiable result under principles of stare

decisis, but would seriously weaken the Court's capacity to exercise the judicial power and to function as the Supreme Court of a Nation dedicated to the rule of law. To understand why this would be so it is necessary to understand the source of this Court's authority, the conditions necessary for its preservation, and its relationship to the country's understanding of itself as a constitutional Republic.

            The root of American governmental powers is revealed most clearly in the instance of the power conferred by the Constitution upon the Judiciary of the United States and specifically upon this Court. As Americans of each succeeding generation are

rightly told, the Court cannot buy support for its decisions by spending money and, except to a minor degree, it cannot independently coerce obedience to its decrees. The Court's power lies, rather, in its legitimacy, a product of substance and perception that shows itself in the people's acceptance of the Judiciary as fit to determine what the Nation's law means and to declare what it demands.

The underlying substance of this legitimacy is of course the warrant for the Court's decisions in the Constitution and the lesser sources of legal principle on which the Court draws. That substance is expressed in the Court's opinions, and our contemporary understanding is such that a decision without principled justification would be no judicial

act at all. But even when justification is furnished by apposite legal principle, something more is required. Because not every conscientious claim of principled justification will be accepted as such, the justification claimed must be beyond dispute. The Court must take care to speak and act in ways that allow people to accept its decision on the terms the Court claims for them, as grounded truly in principle, not as compromises with social and political pressures having, as such, no bearing on the principled choices that the Court is obliged to make. Thus, the Court's legitimacy depends on making legally principled decisions under circumstances in which their principled character is sufficiently plausible to be accepted by the Nation.

The need for principled action to be perceived as such is implicated to some degree whenever this, or any other appellate court, overrules a prior case. This is not to say, of course, that this Court cannot give a perfectly satisfactory explanation in most cases. People understand that some of the Constitution's language is hard to fathom and that the Court's Justices are sometimes able to perceive significant facts or to understand principles of law that eluded their predecessors and that justify departures from existing decisions. However upsetting it may be to those most directly affected when one judicially derived rule replaces another, the country can accept some correction of error without necessarily questioning the legitimacy of the Court.

In two circumstances, however, the Court would almost certainly fail to receive the benefit of the doubt in overruling prior cases. There is, first, a point beyond which frequent overruling would overtax the country's belief in the Court's good faith. Despite the variety of reasons that may inform and justify a decision to overrule, we cannot forget that such a decision is usually perceived (and perceived correctly) as, at the least, a statement that a prior decision was wrong. There is a limit to the amount of error that can plausibly be imputed to prior courts. If that limit should be exceeded, disturbance of prior

rulings would be taken as evidence that justifiable reexamination of principle had given way to drives for particular results in the short term. The legitimacy of the Court would fade with the frequency of its vacillation.

That first circumstance can be described as hypothetical; the second is to the point here and now. Where, in the performance of its judicial duties, the Court decides a case in such a way as to resolve the sort of intensely divisive controversy reflected in Roe and those rare, comparable cases, its decision has a dimension that the resolution of the normal case does not carry. It is the dimension present whenever the Court's interpretation of the Constitution calls the contending sides of a national controversy to end their national division by accepting a common mandate rooted in the Constitution.

The Court is not asked to do this very often, having thus addressed the Nation only twice in our lifetime, in the decisions of Brown and Roe. But when the Court does act in this way, its decision requires an equally rare precedential force to counter the inevitable efforts to overturn it and to thwart its implementation. Some of those efforts may be mere unprincipled emotional reactions; others may proceed from principles worthy of profound respect. But whatever the premises of opposition may be, only the most convincing justification under accepted standards of precedent could suffice to demonstrate that a later decision overruling the first was anything but a surrender to political pressure, and an unjustified repudiation of the principle on which the Court staked its authority in the first instance. So to overrule under fire in the absence of the most compelling reason to reexamine a watershed decision would subvert the Court's legitimacy beyond any serious question....

The country's loss of confidence in the judiciary would be underscored by an equally certain and equally reasonable condemnation for another failing in overruling unnecessarily and under pressure. Some cost will be paid by anyone who approves or implements a constitutional decision where it is unpopular, or who refuses to work to undermine the decision or to force its reversal. The price may be criticism or ostracism, or it may be violence. An extra price will be paid by those who themselves disapprove of the decision's results when viewed outside of constitutional terms, but who nevertheless struggle to accept it, because they respect the rule of law. To all those who will be so tested by following, the Court implicitly undertakes to remain steadfast, lest in the end a price be paid for nothing. The promise of constancy, once given, binds its maker for as long as the power to stand by the decision survives and the understanding of the issue has not changed so fundamentally as to render the commitment obsolete. From the obligation of this promise this Court cannot and should not assume any exemption when duty requires it to decide a case in conformance with the Constitution. A willing breach of it would be nothing less than a breach of faith, and no Court that broke its faith with the people could sensibly expect credit for principle in the decision by which it did that.

It is true that diminished legitimacy may be restored, but only slowly. Unlike the political branches, a Court thus weakened could not seek to regain its position with a new mandate from the voters, and even if the Court could somehow go to the polls, the loss of its principled character could not be retrieved by the casting of so many votes. Like the character of an individual, the legitimacy of the Court must be earned over time. So, indeed, must be the character of a Nation of people who aspire to live according to the rule of law. Their belief in themselves as such a people is not readily separable from their understanding of the Court invested with the authority to decide their constitutional cases and speak before all others for their constitutional ideals. If the Court's legitimacy should be undermined, then, so would the country be in its very ability to see itself through its constitutional ideals. The Court's concern with legitimacy is not for the sake of the Court but for the sake of the Nation to which it is responsible.

The Court's duty in the present case is clear. In 1973, it confronted the already divisive issue of governmental power to limit personal choice to undergo abortion, for which it provided a new resolution based on the due process guaranteed by the Fourteenth Amendment. Whether or not a new social consensus is developing on that issue, its divisiveness no less today than in 1973, and pressure to overrule the decision, like pressure to retain it, has grown only more intense. A decision to overrule Roe's essential holding under the existing circumstances would address error, if error there was, at the cost of both profound and unnecessary damage to the Court's legitimacy, and to the Nation's commitment to the rule of law. It is therefore imperative to adhere to the essence of Roe's original decision, and we do so today.

Question

1. How do you think the Judges in Planned Parenthood would have decided Woods, and vice versa?

Describe the Michelson – Morley Experiment and the main conclusion

A) Use a diagram

Describe the experiment that demonstrated that complete unwinding of the chromosome does not occur

Why was it unnecessary to connect the ground alligator clip in the Oscilloscope experiment