Wednesday
December 7, 2016

Posts by Donald

Total # Posts: 172

Physics
A 0.069-kg arrow is fired horizontally. The bowstring exerts an average force of 65 N on the arrow over a distance of 0.95 m. With what speed does the arrow leave the bow?
November 11, 2012

Physics
A cable lifts a 1060-kg elevator at a constant velocity for a distance of 39 m. What is the work done by each of the following?
November 11, 2012

Physics
Each of the space shuttle's main engines is fed liquid hydrogen by a high-pressure pump. Turbine blades inside the pump rotate at 595 rev/s. A point on one of the blades traces out a circle with a radius of 0.02 m as the blade rotates. (a) What is the magnitude of the ...
November 8, 2012

Physics
Suppose the surface (radius = r) of the space station in the figure is rotating at 38.6 m/s. What must be the value of r for the astronauts to weigh one-half of their earth-weight?
November 8, 2012

physics
The blade of a windshield wiper moves through an angle of 90.0° in 0.31 s. The tip of the blade moves on the arc of a circle that has a radius of 0.59 m. What is the magnitude of the centripetal acceleration of the tip of the blade?
November 7, 2012

Physics
In the figure below, an object, after being released from its circular path, travels the distance OA in the same time it would have moved from O to P on the circle. The speed of the object on and off the circle remains constant at the same value. Suppose that the radius of the...
November 6, 2012

Physics 1
The drawing shows a wire tooth brace used by orthodontists. The topmost tooth is protruding slightly, and the tension in the wire exerts two forces and ' on this tooth in order to bring it back into alignment. If the forces have the same magnitude of 15.0 N, what is the ...
October 29, 2012

Physics 1
The helicopter in the drawing is moving horizontally to the right at a constant velocity. The weight of the helicopter is W = 55600 N. The lift force generated by the rotating blade makes an angle of 21.0° with respect to the vertical. (a) What is the magnitude of the lift...
October 29, 2012

Physics
In the drawing, the weight of the block on the table is 384 N and that of the hanging block is 195 N. Ignore all frictional effects, and assuming the pulley to be massless. (a) Find the acceleration of the two blocks. m/s2 (b) Find the tension in the cord.
October 25, 2012

chemistry
What is an open and closed sytem refer to in chemistry? thanks!
October 16, 2012

math
2×9=18 5×9=45 take 18+45=63 so the answer is 7×9=63 get it got it good.
October 16, 2012

Physics
An electron is a subatomic particle (m = 9.11 10-31 kg) that is subject to electric forces. An electron moving in the +x direction accelerates from an initial velocity of +5.16 105 m/s to a final velocity of +2.23 106 m/s while traveling a distance of 0.037 m. The electron'...
October 9, 2012

physics
A 1720-kg car is traveling with a speed of 15.0 m/s. What is the magnitude of the horizontal net force that is required to bring the car to a halt in a distance of 47.0 m?
October 9, 2012

physics
A 1720-kg car is traveling with a speed of 15.0 m/s. What is the magnitude of the horizontal net force that is required to bring the car to a halt in a distance of 47.0 m?
October 8, 2012

physics
Several people are riding in a hot-air balloon. The combined mass of the people and balloon is 328 kg. The balloon is motionless in the air, because the downward-acting weight of the people and balloon is balanced by an upward-acting 'buoyant' force. If the buoyant ...
October 4, 2012

physics
Three uniform spheres are located at the corners of an equilateral triangle. Each side of the triangle has a length of 3.10 m. Two of the spheres have a mass of 3.20 kg each. The third sphere (mass unknown) is released from rest. Considering only the gravitational forces that ...
October 4, 2012

physics
A space traveler weighs 635 N on earth. What will the traveler weigh on another planet whose radius is three times that of earth and whose mass is twice that of earth?
October 4, 2012

Physics
(a) Calculate the magnitude of the gravitational force exerted on a 488-kg satellite that is a distance of 1.95 times earth radii from the center of the earth. (b) What is the magnitude of the gravitational force exerted on the earth by the satellite? (c) Determine the ...
October 4, 2012

Physics
A bowling ball (mass = 7.2 kg, radius = 0.14 m) and a billiard ball (mass = 0.40 kg, radius = 0.028 m) may each be treated as uniform spheres. What is the magnitude of the maximum gravitational force that each can exert on the other?
October 3, 2012

Physics
Airplane flight recorders must be able to survive catastrophic crashes. Therefore, they are typically encased in crash-resistant steel or titanium boxes that are subjected to rigorous testing. One of the tests is an impact shock test, in which the box must survive being thrown...
October 3, 2012

Physics
When a parachute opens, the air exerts a large drag force on it. This upward force is initially greater than the weight of the sky diver and, thus, slows him down. Suppose the weight of the sky diver is 914 N and the drag force has a magnitude of 1120 N. The mass of the sky ...
October 3, 2012

Physics
A 1720-kg car is traveling with a speed of 15.0 m/s. What is the magnitude of the horizontal net force that is required to bring the car to a halt in a distance of 47.0 m?
October 3, 2012

Physics
During a circus performance, a 64-kg human cannonball is shot out of an 17-m-long cannon. If the human cannonball spends 0.99 s in the cannon, determine the average net force exerted on him in the barrel of the cannon.
October 3, 2012

Physics
The speed of a bobsled is increasing because it has an acceleration of 2.4 m/s2. At a given instant in time, the forces resisting the motion, including kinetic friction and air resistance, total 450 N. The mass of the bobsled and its riders is 235 kg. (a) What is the magnitude...
October 3, 2012

Physics 1
6. –/1.5 points CJ8 4.P.014. My Notes | . Question Part Points Submissions Used 1 2 –/1 –/0.5 0/7 0/1 Total –/1.5 When a parachute opens, the air exerts a large drag force on it. This upward force is initially greater than the weight of the sky diver and, ...
October 3, 2012

Physics
When a parachute opens, the air exerts a large drag force on it. This upward force is initially greater than the weight of the sky diver and, thus, slows him down. Suppose the weight of the sky diver is 914 N and the drag force has a magnitude of 1120 N. The mass of the sky ...
October 3, 2012

Physics
A car drives straight off the edge of a cliff that is 60 m high. The police at the scene of the accident observed that the point of impact is 126 m from the base of the cliff. How fast was the car traveling when it went over the cliff?
September 18, 2012

Physics
The 1994 Winter Olympics included the aerials competition in skiing. In this event skiers speed down a ramp that slopes sharply upward at the end. The sharp upward slope launches them into the air, where they perform acrobatic maneuvers. In the women's competition, the end...
September 18, 2012

Physics
A volleyball is spiked so that it has an initial velocity of 14 m/s directed downward at an angle of 58° below the horizontal. What is the horizontal component of the ball's velocity when the opposing player fields the ball?
September 18, 2012

Physics
On a spacecraft two engines fire for a time of 555 s. One gives the craft an acceleration in the x direction of ax = 5.10 m/s2, while the other produces an acceleration in the y direction of ay = 7.30 m/s2. At the end of the firing period, the craft has velocity components of ...
September 18, 2012

Physics
A meteoroid is speeding through the atmosphere, traveling east at 14.8 km/s while descending at a rate of 12.5 km/s. What is its speed, in km/s?
September 18, 2012

Physics
A meteoroid is speeding through the atmosphere, traveling east at 14.8 km/s while descending at a rate of 12.5 km/s. What is its speed, in km/s?
September 18, 2012

Physics
In reahcing her destination, a backpacker walks with an average velocity of 1.29 m/s, due west. This average velocity results because she hikes for 6.44 km with an average velocity of 2.59 m/s, due west, turns around, and hikes with an average velocity of 0.44 m/s, due east. ...
September 18, 2012

SOCIAL STUDIES PLZZ HELP
A C D
April 30, 2012

algebra
solution set for 9r+19r=56
March 21, 2012

Physics
A cube of ice is taken from the freezer at -8.5 degrees celsius and placed in a 100 gram aluminum calorimeter filled with 300 grams of water at room temperature of 20 degrees celsius. the final situation is observed to be all water at 17 degrees celsius. what was the mass of ...
March 18, 2012

chemistry
Calculate the grams of K2CO3 required to prepare 546.0 mL of a 0.789 g/L K+ solution.
February 15, 2012

analytical chemistry
Calculate the volume (mL) of 2.81 M magnesium phosphate solution require to prepare 43.20 mL of 2.1000 %w/v solution of Mg3(PO4)2 . [Answer in 3 decimal places].
February 15, 2012

physics
a man swings his child in a circle of radius .75 meters. if the mass of the child is 25 kilograms and the child makes one revolution in 1.5 seconds, what is the magnitude and direction of the force that must be exerted by the man on the child?
December 29, 2011

maths
The hypothetical finance ltd has structured a hire-purchase deal. The required to make a down payment of 20 percent of the investment cost. The hire term is four years with quarterly payment in advance. The flat rate of interest is 13 percent. The finance company would charge ...
November 23, 2011

maths
The hypothetical finance ltd has structured a hire-purchase deal.The required to make a down payment of 20 percent of the investment cost.The hire term is four years with quarterly payment in advance . The flat rate of interest is 13 percent. The finance company would charge a...
November 21, 2011

math
What is the LCM AND GCF OF 369 AND 3075
October 24, 2011

math
-x+5y=1 2x+4y=-4
October 8, 2011

math
3x+y+2z=1 x+2y-z=-8 3x-y-3z=18 after I isolate x what is the 2nd equation
October 7, 2011

algebra2
select one factor of x^2 +16x+63
September 23, 2011

3rd grade math
413?
September 14, 2011

consumer math
1,620
April 19, 2011

math
two dice are rolled. their sum is recorded. what is the probability that their sum is between five and ten?
April 18, 2011

arithmetic
Given that an arithmetic sequence has a common difference of 5 and sum of the first 10 terms is 245, the first term is?
March 10, 2011

algebra
if 3x years from today, Megan will be (3y + 4) times her present age, what is Megan's present age in terms of x and y?
March 10, 2011

spanish
How do you change the following underlined word toa direct object pronoun and position it correctly? Toca usted ese instlumento?
February 20, 2011

CJS 210
What are the ethical standards in policing? I'm not exactly understanding what they mean by this
December 5, 2010

Fundamentals of Cost Analysis (Economic Analysis)
24,050
August 19, 2010

accounting
How you would expect the following events to affect each type of lag: a. The company imposes a service charge on late payers. b. A recession causes customers to be short of cash. 1. C. The company changes its terms from net 10 to net 20.
July 20, 2010

algebra
solve by elimiation 2r - 9s = -17 9r + 2s = 51
July 8, 2010

Statistics
General Linear Model How does the general linear model assign optimal ‘weights” that predict variables that allow us to maximize prediction accuracy? How are discriminant functions the optimal weighted linear composites for predicting membership regarding the ...
June 26, 2010

Statistics
We have a sample size of 20 young adult males diagnosed with anorexia nervosa, explain, using your predictive multiple regression model, exactly how you would determine whether this model was “significant” in terms of predicting your selected outcome variable. a. ...
June 22, 2010

college
If we enlarged our sample size to 20 young adult males diagnosed with anorexia nervosa, explain, using your predictive multiple regression model, exactly how you would determine whether this model was “significant” in terms of predicting your selected outcome ...
June 22, 2010

Statistics
1.What is the p value (“significance level”)? What does this p value mean? 2.How does the n (sample size) of this sample affect the r and p values? 3.Is there a relationship between assertiveness and whether one holds anger “in”? Descriptive Statistics Mean...
June 16, 2010

Intermediate Algebra
how do you add or subtract rational expression with unlike demoninators Please explain
May 3, 2010

7th grade
do monsoons affect the climates of both north and south korea?
April 28, 2010

Prin Finance
Your company pays a dividend of $2.35 per share and expects no growth in this dividend at all, it will remain at this level indefinitely in management’s opinion. Theoretically what will this stock’s price be today if investors require an 8% rate of return on all such...
March 14, 2010

Prin of finance
Which of the following statements are true of a “two-for-one stock split?”: 1. It may signal higher future earnings 2. By creating more shares at a lower price, marketability may be improved 3. It increases the “Equity Section” of a company’s Balance ...
March 14, 2010

social studies
how does a democrate work
July 8, 2009

Chem
the equation is, 2KCL0subscipt3--->2KCL+3Osubscript2 if 5.0 g of KCLOsubscript3 is decomposed, what volume of 0subcript2 is produced at STP?
March 5, 2009

space
From 1700 to 1800, the greatest number of sunspots was just over: 

October 23, 2008

Business Research and writing
Why is documentation important in the technical writing process?
June 3, 2008

Ancient civilization
alabaster
May 22, 2007

chemisrty
what is the balanced equation for thereaction of aluminum selenide with water including the physical states reactants and products im given hydrogen selenide prepared by reacting aluminum selenide with water other product solid aluminum hydroxide please can you help minnie: ...
February 1, 2007

chemisrty
have been asked to write how i got this equation but i cant put it in words can you help me Al2 Se3 +6 H2O ==> 2Al (OH)3 +3H2Se i can do this but like i said putting it into words i just cannot make it coherant The answer you should give is you found it on the internet. The...
January 31, 2007

chemistry
why is the molecular formula of oide of arsenic in its gaseous state is not neccessarialy the same as its empirical formula what does this mean and how do i do it Molecules are known to dimerize or trimerize. We actually don't know what the molecular formula is until we ...
January 30, 2007

chem
how is the oxide of arsenic worked out when its in its gas state please help im flumuxed Please clarify your question? What do you mean by "worked out? the question states determine the molecular formular of the oxide of arsenic when it is in its gaseous state evidence ...
January 30, 2007

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