Questions
An experiment on tethered mine motions is to be conducted in fresh water in a wave...

An experiment on tethered mine motions is to be conducted in fresh water in a wave tank. The mine is a sphere of 5cm diameter made of polystyrene (weight assumed negligible). The anchoring block is a lead cube of side length 5cm. The specific gravity of lead is 14.0. If the mine is joined to the lead cube by a light chord such that it floats completely submerged just below the free surface, determine:

a) the tension in the chord

b) the reaction force between the lead cube and the bottom of the tank.

In: Mechanical Engineering

The purpose of this experiment was to determine the equilibrium constant of the reaction between iron...

The purpose of this experiment was to determine the equilibrium constant of the reaction between iron (III) chloride (FeCl3) and potassium thiocyanate (KSCN) through the use of spectrophotometry.

Part A: Producing the calibration curve

Part B: FInding the equilibrium concentraions

Why were FeCl3 and HCl added to the blank solutions? Why not just use distilled water for the blanks? Why would you use two different blank solutions for parts A and B?

In: Chemistry

The data for an Enzyme with a Kcat is 5,000m-1. This experiment was performed by adding...

The data for an Enzyme with a Kcat is 5,000m-1. This experiment was performed by adding a given amount of substrate of 100 micrograms of enzyme in buffer solution. What is the molecular weight of the enzyme?

Substrate Concentration mM rate (Vo) micromol/min
1 167
2 250
4 334
6 376
100 498
1000 499

In: Chemistry

A. In the experiment, The molar volume of a gas. Mg (s) + 2HCl (aq) =...

A. In the experiment, The molar volume of a gas. Mg (s) + 2HCl (aq) = MgCl2​ (aq) + H2 ​(g), the magnesium ribbon was dissolved in hydrochloric acid, a monoprotic acid, to produce H2 ​gas. If phosphoric acic, a triprotic acid, were used to react with the magnesium rather than hydrochloric acid, does that affect the amount of H2​ gas produced?. Write balanced equations for the reaction og Mg with 1) HCl and 2) phosphoric acid to help explain your answer.

B. In this experiment, Mg (s) + 2HCl (aq) = MgCl2​ (aq) + H2 ​(g), ​you injected 5 ml of HCl into the flask and immediately pulled back the plunger to its original position. Explain (a) why this latter action was done and (b) if the plunger weren't pulled back to its original position, how would this affect the subsequent molar volume calculation (say, under STP condictions). Answer this question by stating the molar volume calculation would be higher, lower, or not affected, and proide a plausible explanation for your choice.

In: Chemistry

In a controlled experiment, it takes 3700 J to melt the amount of metal that is...

In a controlled experiment, it takes 3700 J to melt the amount of metal that is in a weld bead with a cross-sectional area of 6.0 mm2 that is 150.0 mm long. (a) Using Table 28.2, what is the most likely metal? (b) If the heat transfer factor is 0.85 and the melting factor is 0.55 for a welding process, how much heat must be generated at the welding source to accomplish the weld?

In: Mechanical Engineering

An article in Journal of Structural Engineering presents the results of an experiment that evaluated a...

An article in Journal of Structural Engineering presents the results of an experiment that evaluated a standard method for estimating the brace force for a truss. In a sample of 360 short test trusses the method underestimated the force for 45 of them, and in a sample of 400 long test trusses, the method underestimated the force for 60 of them. Find a 95% confidence interval for the difference between the underestimation rates for long and short trusses.

In: Statistics and Probability

An experiment was conducted to test the effect of a new drug on a viral infection....

An experiment was conducted to test the effect of a new drug on a viral infection. After the infection was induced in 100 mice, the mice were randomly split into two groups of 50. The first group, the control group, received no treatment for the infection, and the second group received the drug. After a 30-day period, the proportions of survivors, p?1 and p?2, in the two groups were found to be 0.32 and 0.60, respectively.

(a) Is there sufficient evidence to indicate that the drug is effective in treating the viral infection? Use ? = 0.05.

State the null and alternative hypotheses.

H0: (p1 ? p2) ? 0 versus Ha: (p1 ? p2) = 0H0: (p1 ? p2) = 0 versus Ha: (p1 ? p2) ? 0    H0: (p1 ? p2) = 0 versus Ha: (p1 ? p2) > 0H0: (p1 ? p2) = 0 versus Ha: (p1 ? p2) < 0H0: (p1 ? p2) < 0 versus Ha: (p1 ? p2) > 0


Find the test statistic and rejection region. (Round your answers to two decimal places. If the test is one-tailed, enter NONE for the unused region.)

test statistic     z =
rejection region     z >
    z <


State your conclusion.

H0 is rejected. There is sufficient evidence to indicate that the drug is effective in treating the viral infection.H0 is not rejected. There is insufficient evidence to indicate that the drug is effective in treating the viral infection.    H0 is not rejected. There is sufficient evidence to indicate that the drug is effective in treating the viral infection.H0 is rejected. There is insufficient evidence to indicate that the drug is effective in treating the viral infection.


(b) Use a 95% confidence interval to estimate the actual difference (p1 ? p2) in the survival rates for the treated versus the control groups. (Round your answers to two decimal places.)
to

In: Statistics and Probability

An experiment is to be conducted using a crossover design. The statistician informs the investigator that...

  1. An experiment is to be conducted using a crossover design. The statistician informs the investigator that a rest period, or washout period, should be included in the study plan. The purpose of the rest period is to eliminate or reduce (1 mark)
  1. Observer data
  2. Missing data
  3. Residual treatment effects
  4. Problems with patient compliance
  5. Adverse drug experiences

In: Statistics and Probability

An experiment was conducted to test the effect of a new drug on a viral infection....

An experiment was conducted to test the effect of a new drug on a viral infection. After the infection was induced in 100 mice, the mice were randomly split into two groups of 50. The first group, the control group, received no treatment for the infection, and the second group received the drug. After a 30-day period, the proportions of survivors, p?1 and p?2, in the two groups were found to be 0.36 and 0.64, respectively.

(a) Is there sufficient evidence to indicate that the drug is effective in treating the viral infection? Use ? = 0.05.

State the null and alternative hypotheses.

H0: (p1 ? p2) < 0 versus Ha: (p1 ? p2) > 0

H0: (p1 ? p2) = 0 versus Ha: (p1 ? p2) < 0

H0: (p1 ? p2) ? 0 versus Ha: (p1 ? p2) = 0

H0: (p1 ? p2) = 0 versus Ha: (p1 ? p2) ? 0

H0: (p1 ? p2) = 0 versus Ha: (p1 ? p2) > 0

Find the test statistic and rejection region. (Round your answers to two decimal places. If the test is one-tailed, enter NONE for the unused region.)

test statistic: z =

rejection region: z >, z <

State your conclusion.

H0 is not rejected. There is insufficient evidence to indicate that the drug is effective in treating the viral infection.

H0 is rejected. There is sufficient evidence to indicate that the drug is effective in treating the viral infection.

H0 is not rejected. There is sufficient evidence to indicate that the drug is effective in treating the viral infection.

H0 is rejected. There is insufficient evidence to indicate that the drug is effective in treating the viral infection.

(b) Use a 95% confidence interval to estimate the actual difference (p1 ? p2) in the survival rates for the treated versus the control groups. (Round your answers to two decimal places.)

_____ to _____

You may need to use the appropriate appendix table or technology to answer this question.

In: Statistics and Probability

Density of plastic Your challenge in this experiment is to determine the density of a mystery...

Density of plastic

Your challenge in this experiment is to determine the density of a mystery plastic, using two different step-by-step procedures. For sufficient error analysis, each method should be completed at least twice (e.g., Method A: Trial #1 & Trial #2; Method B: Trial #1 & Trial #2).
The plastic is in the form of small (~1 cm), irregularly shaped pieces. You will have access to several pieces of the plastic. The irregular shapes mean that it will not be possible to calculate the volume of the pieces by measuring their dimensions. In addition to the normal chemistry laboratory equipment and water, there will be methanol and ethylene glycol available in the lab this week.

My question is

Write two detailed, step-by-step procedures that use different ways to determine the density of the plastic.

In: Chemistry