Problem A stone is thrown from the top of a
building with an initial velocity of 24.3 m/s straight upward, at
an initial height of 53.1 m above the ground. The stone just misses
the edge of the roof on its way down, as shown in Figure
2.20.
(a) Determine the time needed for the stone to
reach its maximum height.
(b) Determine the maximum height.
(c) Determine the time needed for the stone to
return to the height from which it was thrown, and the velocity of
the stone at that instant.
(d) Determine the time needed for the stone to
reach the ground.
(e) Determine the velocity and position of the
stone at t = 5.68 s.
| (a) Find the time when the stone reaches its maximum height. | ||
| Write the velocity and position kinematic equations. | v
= at + v0 Δy = y - y0 = v0t + at2 |
|
| Substitute a = -9.80 m/s2, v0 = 24.3 m/s, and y0 = 0 into the preceding two equations. | v = (-9.80
m/s2)t + 24.3
m/s (1) y = (24.3 m/s)t - (4.90 m/s2)t2 (2) |
|
| Substitute v = 0, the velocity at maximum height, into Equation (1) and solve for time. | 0 = (-9.80
m/s2)t + 20.0 m/s s |
|
| (b) Determine the stone's maximum height. | ||
| Substitute the time found in part (a) into Equation (2). | ymax = (24.3 m/s)(t s) - (4.90 m/s2)(t s)2 = m | |
| (c) Find the time the stone takes to return to its initial position, and find the velocity of the stone at that time. | ||
| Set y = 0 in Equation (2) and solve for t. | 0 = (24.3 m/s)t -
(4.90 m/s2)t2 = t(24.3 m/s - 4.90 m/s2t) t = s |
|
| Substitute the time into Equation (1) to get the velocity. | v = 24.3 m/s +
(-9.80 m/s2)(t) v = m/s |
|
| (d) Find the time required for the stone to reach the ground. | ||
| In Equation (2), set y = -53.1 m. | -53.1 m = (-24.3 m/s)t - (4.90 m/s2)t2 | |
| Apply the quadratic formula and take the positive root. | t = s | |
| (e) Find the velocity and position of the stone at t = 5.68 s. Substitute values into Equations (1) and (2). | v = (-9.80
m/s2)(5.68 s) + 24.3 m/s v = m/s y = (24.3 m/s)(5.68 s) - (4.90 m/s2)(5.68 s)2 y = m |
|
In: Physics
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Required:
a. Do you think these findings represent valid relationships or spurious correlations?
b. What measures do you think might be valid predictors of stock market returns?
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A program director for a large computer maker is evaluating a circuit-designing software package. Not only is the program purported to ease the engineer’s tasks, but its author also claims that the finished products will be more economical because fewer logical elements will be needed. To test this theory, the software was borrowed and used to redesign 20 prototype circuits already completed the traditional way. The resulting computer-generated designs all worked and involved a mean percentage reduction in components of 3.4% (S = 4.2%). a) At the 1% significance level, can the project manager reject the hypothesis that the software design involved at least as many elements as do traditional ones? b) What is the smallest significance level at which the null hypothesis can be rejected?
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In: Statistics and Probability
True or False?
a) Calculation of retained earnings is one of the factors cited by our author for why NI and CF may be different.
b)
COGS appears on the asset side of the BS.
C)
?EBIT can be found by subtracting SGA and Depreciation from the gross profit margin.
D)
?Changes in interest expense do not affect a? firm’s cash position.
E)
The balance sheet identity indicates that total liabilities can be found by adding total assets to total equity.
F)?If there is no change in gross fixed assets from one year to the? next, then net fixed assets would have to have increased.
G)Accounts payable represents? short-term loans extended to the corporation by suppliers.
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Accrual accounting matches revenue with expenses, however accruals can be used to manipulate income and expenses. In the Forbes Magazine article, “Cash Doesn’t Lie,” written by Daniel Fisher, the author discusses the use of negative accruals, changes to estimates and recognizing income before it is earned. Read the article and then:
a. Discuss the use of each of these three techniques and their
effect on current and future earnings reporting.
b. How should changes of accounting estimates that significantly
affect income be reported? Should they be regarded as a change in
accounting principle?
c. Research revenue recognition and discuss the accounting rules
violated that brought down the company Sunbeam.
PLEASE PROVIDE NEW DETAIL ANSWERS TO EACH QUESTION AND PLEASE NO HAND WRITTEN ANSWERS.
In: Accounting
For this assignment, you will select an article from a print or online news source that addresses economic issues or problems in an editorial fashion (you can also use political cartoons or memes that are presented as providing factual information). Using the tools of analysis, you should briefly (1-2 paragraphs) summarize the article, and then analyze and critique the article. You must critique the article and not merely summarize it. Your paper should be well-written and should reflect your current knowledge of economic theory (as limited as it is). (Hint: A good starting point is to identify the assumptions of the author.)
You may select and article of your choice about an economic issues or problem
Please provide the source/article chosen
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