A polytropic process (n= 1.25) compresses air from 0.3 m3 at 22 0C and pressure of 125 kPa to 0.15 m3. It is then expanded at constant temperature to its original volume.
In: Mechanical Engineering
LetXbe a discrete random variable with the following PMF:
P(X=x) =
0.3 for x = 1,
a for x = 2,
0.5 for x= 3,
0 otherwise
(a) Find the value of a.
(b) Find Fx(x), the CDF of X.
(c) What is the value of Fx(2)?
(d) Find E[X].
(e) FindE[X^2].
(f) Find V ar(X)
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A certain area of the eastern United States is, on average,hit by 2 hurricanes a year. Find the probability that the area will be hit byexactly 3 hurricanes in a given year.
In: Statistics and Probability
32. Every day, Jorge buys a lottery ticket. Each ticket has a probability of 0.3 of winning a prize. After seven days, what is the probability that Jorge has won at least one prize? Round your answer to four decimal places.
26. Charles has seven songs on a playlist. Each song is by a different artist. The artists are Shania Twain, Nick Carter, Aaron Carter, Joey McIntyre, Phil Collins, Shakira, and Michael Jackson. He programs his player to play the songs in a random order, without repetition. What is the probability that the first song is by Nick Carter and the second song is by Joey McIntyre? Write your answer as a fraction or a decimal, rounded to four decimal places.
25. An unfair coin has probability 0.3 of landing heads. The coin is tossed seven times. What is the probability that it lands heads at least once? Round the answer to four decimal places.
21. Let A and B be events with =PA0.7 and =PB0.5. Assume that A and B are independent. Find PA and B.
In: Statistics and Probability
A heavy rope, 40 feet long, weighs 0.3 lb/ft and hangs over the
edge of a building 110 feet high. Let x be the distance in feet
below the top of the building.
Find the work required to pull the entire rope up to the top of the
building.
1. Draw a sketch of the situation.
We can look at this problem two different ways. In either case, we
will start by thinking of approximating the amount of work done by
using Riemann sums. First, let’s imagine “constant force changing
distance.”
2. Imagine chopping the rope up into n pieces of length ∆x. How
much does each little
piece weigh? (This is the force on that piece of rope. It should be
the SAME for each
piece of rope.)
3. How far does the piece of the rope located at xi have to travel
to get to the top of the
building? (Notice that this is DIFFERENT for each piece of rope; it
depends on the
location of the piece.)
4. How much work is done (approximately) to move one piece of rope
to the top of the
building?
5. Find the amount of work required to pull the entire rope to the
top of the building,
using an integral.
Now, let’s do the same problem, but this time, imagining “constant
distance, changing force.” Imagine pulling up the rope a little bit
at a time, say, we pull up ∆x feet of rope with each pull.
6. After you have pulled up xi feet of rope, how much of the rope
remains to be pulled?
7. What is the force on the remaining amount of rope?
8. Remembering that each pull moves the rope ∆x feet, how much work
is done for each
pull?
9. Find the amount of work required to pull the entire rope to the
top of the building,
using an integral.
Help 6 to 9 and write it in order with number.
In: Math
Calculate the pH during titration of 25 mL of 0.175 M HCN with 0.3 M NaOH after the addition of 0 mL, 7.29mL, 14.5833 mL, and 20 mL base. Kb of CN- is 2.03 x 10^-5. Show all work.
In: Chemistry
A mass of 0.3 kg hangs motionless from a vertical spring whose length is 1.05 m and whose unstretched length is 0.40 m. Next the mass is pulled down to where the spring has a length of 1.30 m and given an initial speed upwards of 1.9 m/s. What is the maximum length of the spring during the motion that follows?
In: Physics
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Question 1 1 pts
Calculate the molarity of 2.45 mol CaCl2 in 0.3 L solution.
| 8.16 M |
| 0.735 M |
| 0.122 M |
| 5.42 M |
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Question 2 1 pts
What are the products of this acid-base reaction: HI(aq) + Ba(OH)2(aq)?
| BaI2 and H2O |
| BaH2 and I(OH)2 |
| BaO and H2O |
| BaI2 and 2OH- |
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Question 3 1 pts
Write the complete ionic equation for: Pb(NO3)2(aq) + 2KCl(aq) -->PbCl2(s) + 2KNO3(aq)
| Pb2+(aq) + 2NO3-(aq) + 2K+(aq) + 2Cl-(aq) -> PbCl2(s) + 2K+(aq) + 2NO3-(aq) |
| Pb2+(aq) + 2NO3-(aq) + 2K+(aq) + 2Cl-(aq) -> Pb2+(aq) + 2NO3-(aq) + 2KCl(aq) |
| Pb2+(aq) + 2NO3-(aq) + 2K+(aq) + 2Cl-(aq) -> Pb2+(aq) + 2Cl-(aq) + 2KNO3-(aq) |
| Pb2+(aq) + 2NO3-(aq) + 2K+(aq) + 2Cl-(aq) -> Pb2+(aq) + 2Cl-(aq) + 2K+(aq) + 2NO3-(aq) |
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Question 4 1 pts
What is the molarity of CO32- in 0.24 M Al2(CO3)3?
| 0.72 M |
| 0.48 |
| 0.24 M |
| 0.08 M |
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Question 5 1 pts
If 430 mL of a 5.5 M glucose solution is diluted to 1500 mL, what is the molarity of the diluted solution?
| 1.58 M |
| 2.0 M |
| 0.13 M |
| 3.2 M |
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Question 6 1 pts
To what volume would you dilute 35 mL of a 9.5 M stock HCl solution to obtain a 1.4 M HCl solution?
| 238 mL |
| 530 mL |
| 300 mL |
| 425 mL |
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Question 7 1 pts
What volume of 2.5 M glucose solution contains 0.78 mols of glucose?
| 0.312 L |
| 0.631 L |
| 0.095 L |
| 2.5 L |
In: Chemistry
A mass of 0.3 kg hangs motionless from a vertical spring whose length is 0.88 m and whose unstretched length is 0.48 m. Next the mass is pulled down to where the spring has a length of 1.08 m and given an initial speed upwards of 1.9 m/s. What is the maximum length of the spring during the motion that follows?
In: Physics
use a matlab built-in function to numerically solve:
dy/dx= -x^2+((x^3*e^-y)/4) for 1<=x<=5 with y(1)=1
plot the solution
In: Mechanical Engineering
In: Electrical Engineering