Total # Posts: 2,457
B) A random sample of 16 mid-sized cars tested for fuel consumption gave a mean of 26.4Kilometers per liter with a standard deviation of 2.3 kilometers per liter. i) Assuming that the kilometers per liter given by all mid-sized cars have a normal distribution, find a 99% ...
September 26, 2016
A) Daily sales of petrol from the Nabua service station are normally distributed with Mean6300Landthe standard deviation 400L. (i) If a daily sale is selected at random, find the probability that it is less than 6200L. (ii) If petrol sales are sampled for 40 days, and the ...
September 25, 2016
Two trains whose rates differ by six miles per hour start at the same time from stations that are 273 miles apart. They meet in three and a half hours. Find the rate of each train.
September 25, 2016
Let z and w be complex numbers such that |z| = |w| = 1 and zw does not equal -1. Prove that (z + w) / (zw + 1) is a real number. I have tried to rationalize the denominator and I got (z^2*w-z*w^2) / (zw)^2-1 but that got me nowhere. Can someone please help me!!!
August 15, 2016
Convert ( 4, -pi/6) from polar coordinates to rectangular coordinates. I got sqrt 12, -2 as my answer but it said this was wrong. I checked multiple times and I don't see where I messed up
August 5, 2016
Please Help A body consists of a solid hemisphere of radius r joined to a right circular cone of base radius r and perpendicular height h. The plane surfaces of the cone and hemisphere coincide and both solids are made of the same material. Show that the centre of gravity of ...
July 24, 2016
A girl sees her image in a shiny glass sphere tree ornament that has a diameter of 18 cm. The image is upright and is located 2.9 cm behind the surface of the ornament. How far from the ornament is the child located? The child is located cm in front of the ornament.
July 18, 2016
A copper wire that has a diameter of 2.9 mm carries a current of 39.0 A. Assuming that each copper atom contributes one free electron to the metal, find the drift velocity of the electrons in the wire. The molar mass of copper is 63.5 g/mol and the density of copper is 8.95 g/...
July 6, 2016
During a thunderstorm, a lightning bolt carries current between a cloud and the ground below. If a lightning bolt transports a total charge of 80 C in 0.001 s, what is the magnitude of the average current? A
July 6, 2016
A stone is dropped from the root of a building. A person in the building observes that the stone crosses his window that is 2 meters tall in a time of 0.2 second. How far is the roof from the top of the window?
June 30, 2016
A cyclist is on a rolling stationary trainer pedaling such that his wheels are traveling at 30 km/h. He has an unfortunate incident and ends up falling over 90° on his side onto a large patch of ice. Given the cyclist and bicycle have an 4.5 kg*m^2, find the angular ...
June 30, 2016
A dolphin wants to swim directly back to its home bay, which is 0.800 km due west. It can swim at a speed of 3.58 m/s relative to the water, but a uniform water current flows with speed 2.95 m/s in the southeast direction.
May 29, 2016
The heights of Japanese maple trees are normally distributed with a mean of 6 meters and a standard deviation of 0.2 meter. What percent of Japanese maple trees are between 5.5 meters and 6.7 meters tall?
May 25, 2016
In how many ways can a committee of 12 people, of which 5 must be in the 21−30 age group, 4 must be in the 31−40 age group and 3 must be in the 41−50 age group, be chosen if there are 6 people of each age group?
May 12, 2016
In a card game player get at the start 2 green cards, 3 blue cards, 4 red cards, and 3 yellow cards. In how many ways can the player get cards at the start if this card game has 7 green, 7 blue, 10 red and 10 yellow cards?
May 12, 2016
Suppose a tortoise is 2000 feet from the ocean. Each day the tortoise travels one-half of the remaining distance to the ocean. Use this information to: Compute the remaining distance to the ocean after 4 days of travel.
May 1, 2016
Atmospheric pressure decreases by about 12% for every kilometer you climb. The pressure at sea level is about 1013 atmospheres. How many atmospheres of pressure will you feel at 8.848 km?
May 1, 2016
The Davidson family wants to expand its rectangular patio, which currently measures 15 ft by 12 ft. They want to extend the length and width the same amount to increase the total area of the patio by 160 ft2. Which quadratic equation best models the situation? A = lw (15)(12...
April 29, 2016
Can somebody check over my answers my answers are : B;C;B;A;D;C;A;B;D;C;A;B;B;B;C;D;A;A;B;C; C;D;1. Trench warfare caused the immobilization of troops on the (1 point)Western Front.Middle Eastern desert.Eastern Front.mountains in Russia.2. After the war, Britain ruled ...
April 20, 2016
The Northwest Ordinance established all of the following, except rules for territories to become states. denying slavery to new states formed from the territory. preventing new states from entering the United States. the right to education (------my choice
April 15, 2016
A geostationary satellite orbits the Earth in such a manner that it is always directly above the same point on the equator as the Earth rotates. Assuming that this orbit is circular, what is its radius? (The mass of the Earth is approximately 5.97 × 1024 kg and the ...
April 15, 2016
A 40.0 ohm resistor, 20.0 ohm resistor, and a 10.0 ohm resistor are connected in series across a 220-V supply. Which resistor is the warmest? a. 40.0 ohm b. 20.0 ohm c. 10.0 ohm d. they are all the same
March 18, 2016
An object is launched at 9.8 meters per second from a 73.5-meter tall platform. The object's height s (in meters) after t seconds is given by the equation s(t)= -4.9t(-4.9t) - 9.8t = 73.5. When does the object strike the ground? I can't figure out how to factor it ...
March 11, 2016
assume that 13.5g of AL react with excess HCl according to the following balanced equation, at STP: 2Al(s) + 6HCl(aq) ---> 2AlCl3 + 3H2(g) how mang liters of H2 at STP are produced?
March 6, 2016
A circuit consists of a 10 ohm resistor in series with 3 identical batteries each with an emf = 1.0V and internal resistance of 5 ohms. a) find potential difference between the terminals b) potential difference across the 10 ohm resistor c) power dissipated in resistor
March 3, 2016
Find the length of the entire perimeter of the region inside r=5sin(theta) but outside r=1. 1=5sin(theta) theta=arcsin(1/5) r'=5cos(theta) I tried the integral between arcsin(1/5) and pi-arcsin(1/5) of (((5sin(theta))^2+(5cos(theta))^2))^1/2 which gives me 13.694 Webworks...
February 19, 2016
A bullet of mass 3.9 g was fired at a stationary ball of lead. The head on impact moved the 10 kg ball at a velocity of .3703 m/s. If energy losses due to heat and internal energy are ignored. What was the speed of the bullet? a)370 b)950 c)549 d)975
February 13, 2016
A bullet of mass 3.9 g was fired at a stationary ball of lead. The head on impact moved the 10 kg ball at a velocity of .3703 m/s. If energy losses due to heat and internal energy are ignored. What was the speed of the bullet?
February 12, 2016
In The Importance of Being Earnest, Jack and Algernon clearly have a preoccupation with food. Discuss how food serves as a symbol for obedience to impulse and the pursuit of pleasure. How does this symbol help Oscar Wilde to comment on and satirize society?
February 11, 2016
Bett, Cathy, Isabel, Lani and Ursula run an 800-meter race. Betty beat Cathy by 7 meters. Alma finished 12 meters behind Lani. Bettty finished 5 meters ahead of Ursula but 3 meters behind Lani. Isabel finished halfway between the first and last person. In what order did they ...
February 2, 2016
A 1" x 1" 1/8" copper ingot has a density of 8.94 g/mL. 25 pellets were obtained from the ingot. Explain what would be the density of each pellet. I went ahead and found the mass of the ingot which is 1.1175g but I'm still stumped on what to do from there.
February 1, 2016
A thin metallic spherical shell of radius .5m has a total charge of 8 μC uniformly distributed on it. At the center of the shell is placed a point charge of 4 μC. What is the electric field at a distance of .15 m from the center of the spherical shell? I know that EA...
January 27, 2016
the pressure at a point below a point below the surface of the sea is caused by both the height of the water above that and the air pressure on the surface of the sea. if the diver reaches a depth of 20m below the surface on the surface of the sea Calculate The total pressure ...
January 26, 2016
A proton is released from rest inside a region of constant, uniform electric field E1 pointing due North. 14.8 seconds after it is released, the electric field instantaneously changes to a constant, uniform electric field E2 pointing due South. 8.07 seconds after the field ...
January 23, 2016
There are 20 questions in a test. Faye answers 17 correctly. a. What fraction of questions does faye answer correctly? b. What percentage of the questions does Faye answer correctly?
January 14, 2016
It is 780 km from Lethbridge to Fort McLeod. One plane leaves from Lethbridge going 200 km/h. A second plane leaves from Fort McLeod going 300 km/h. When do they pass in the sky?
January 12, 2016
The force on a .4 kg cannon ball in the barrel when fired at t=0 seconds is given by F= 1000- 5 * 10^4t. The acceleration of the ball is 0 as it leaves the barrel The total impulse in Newton seconds on the ball during the .02 seconds it's in the barrel would be
January 5, 2016