A motorist A leaves a small town and drives East at 28 ms-1 . A second motorist B is driving South towards the same town at 23 ms-1 . Draw a diagram and find the velocity of motorist B relative to motorist A? ( VB REL A ) is this just phythagoras and finding the resultant ...
August 22, 2014
An object 3.60 cm tall is placed 13.1 cm in front of a mirror, which creates an upright image that is 5.21 cm in height. a) What is the magniﬁcation of the image? b) What is the radius of curvature of the mirror? Answer in units of cm
May 19, 2014
A spacecraft of mass m is first brought into an orbit around the earth. The earth (together with the spacecraft) orbits the sun in a near circular orbit with radius R (R is the mean distance between the earth and the sun; it is about 150 million km). (a) What is the speed v0 (...
November 20, 2013
identify and explain at least one real-world application of mathematical concepts covered in the text, your job or daily life, for one of the following areas: business, health and wellness, science, sports, and environmental sustainability. Do you think it is easier to relate ...
July 23, 2013
A number written in scientific notation has to be between 1 and 10. The 10 to whatever power tells you whether to move the decimal point right or left depending on whether it is positive or negative. So for number one, the answer has to be 4. The actual number is 0.0042 ...
January 31, 2013
One ship is 20 miles due North of another ship, and is sailing South at the rate of 10 miles per hour. The second ship sails West at the rate of 20 miles per hour. For how long will the ships continue to approach each other?
November 14, 2012
An airplane is flying horizontally with a constant velocity of 160 m/s at an altitude of 5100 m when it releases a package. a. How long does it take for the package to reach the ground? (Ignore air resistance.) b. What is the distance between the airplane and the package when ...
September 19, 2012
In order to test a new production method, 36 employees were selected randomly to try the new method. The mean was 75.79 parts per hour with a standard deviation of 28.25 parts per hour. Calculate a 95% confidence interval for the true mean production rate for the new method.
June 13, 2012
The ammeter your physics instructor uses for in class demonstrations has a resistance R(g)= 60 ohms and requires a current of 1.0 mA for a full scale deflection. The same ammeter can be used to measure currents of much greater values by wiring a shunt resistor of relatively ...
November 23, 2011
Capacitor A has a capacitance CA =29.4 uF and us initially charged to a voltage of V1= 10.70 V. Capacitor B is initially uncharged . When the switches are closed, connecting the two capacitors, the voltage on capacitor A drops to V2 = 6.40 V. What is the capacitance CB (in uF...
November 23, 2011
A 2kg hallow sphere of a radius 6cm starts from rest and rolls without slipping down a 10 degree incline. if the length of the incline is 50cm then the velocity of the center of mass of the hallow sphere at the bottom of the incline is?
October 26, 2011
The numerator of a fraction is two less than its denominator. When both numerator and denominator are increased by 3, the fraction is increased by 3/20. Find the original fraction. Explain your solution
October 22, 2011
A tortoise can run at a speed of 20 cm/s and a hare can run exactly 20 times as fast. In a race, they both start at the same time but the hare stops to rest for 2.00 mins. The tortoise wins by 20.0 cm. How long does the race take? What is the length of the race?
September 22, 2011
Stan takes a trip, driving with a constant velocity of 81.5 km/h to the north except for a 22 min rest stop. If Stan's avg velocity is 66.80 km/h to the north, how long does the trip take?
September 22, 2011
An antelope has traveled 1.60 km at avg speed of 67.0 km/h. The antelope speed during the first half of the distance is 88km/h. Find the antelope's avg speed during the second half of the run.
September 22, 2011
According to the experiment procedure, given that the NaOH solution has a concentration of 0.100M, and that the vinegar (acetic acid) has a concentration of 5.0%m/m (mass percent), what volume(mL) of titrant would be required to reach the "equivalence point", if you ...
July 24, 2011
2 birds fly from their nest to get to a certain spot(food) in a straight line,from opposite directions (east-west) Both fly 60 km/hr.but one has a 44 km/hr tailwind to his advantage(disadvantage for the other.The bird with the advantage gets to the feeding spot 1 minute before...
January 23, 2011
Chem! Please helpppp!!!!!
Consider the evaporation of methanol at 25.0 c: CH3OH(l)-- CH3OH(g) I figured out that Delta G is 4.3 kJ. Find the Delta G at 25 C under the following conditions: Pressure of CH3OH= 157mmHg, 103mmHg, 14mmHg thanks! please explain
November 11, 2010
Suppose that the radius r of a right circular cone of fixed height h = 30 cm is increasing at a rate 10 cm/s. How fast is the volume increasing when r = 15? Give your answer correct to two decimal places.
October 12, 2010
Maximize P = 16x + 80y subject to these constraints: 2x + 20y ≤ 430 4x + 70y ≤ 1400 8x + 30y ≤ 980 10x + 10y ≤ 1000 4x + 30y ≤ 700 x ≥ 0, y ≥ 0 Maximum value for P = ?. This value of P occurs when x = ? and y = ? If u1, u2, u3, u4, and...
September 20, 2010
Delta Software is considering a new project whose data are shown below. The equipment that would be used has a 3-year tax life, after which it will be worthless, and it will be depreciated by the straight line method over 3 years. Revenues and other operating costs are ...
May 16, 2010
A 74 kg adult sits at one end of a 8.5 m long board. His 35 kg child sits on the other end.Where should the pivot be placed so that the board is balanced, ignoring the board's mass?
April 20, 2010
The demand and supply curves for an import-competing industry in a country are given by: D = 500 10P, S = 100 + 10P. Similarly, the respective demand and supply curves of foreign country for this industry are given by D* = 400 10P, S* = 200 + 10P. a. What will be...
March 22, 2010
The question is: A 30g sample of metal with a specific heat of .34J/g is heated to 50C. 4.8KJ of energy was transferred. What is the initial temperature? I used: heat=(mass)(specific heat)(change in temp) So I did 4800J=(30)(.34)(50-x) 4800=(10.2)(50-x) 4800=510-10.2x 4290=10....
March 1, 2010
I need to find heat of vaporization. The liquid starts to vaporize at 110 degrees C and there is 10 g of the liquid. I don't think it matters but it is heated at 60 kj/minute. Would it just be amount multiplied by the temp when it starts to vaporize? I don't think it ...
February 19, 2010
If a pronghorn antelope accelerates from rest in a straight line with a constant acceleration of 1.4m/s^2, how long does it take for the antelope to reach a speed of 23 m/s? Ans in s
January 29, 2010
Use the graph, showing the yearly food costs of a family. What was the percent decrease in the cost of food from 2003 to 2004? Your answer must be a percentage. 2003 is 10,500 and 2004 is 9,500
March 29, 2009
1) Solve for x and check Radical (x^2-10x)=3i 2) Simplify (5+ Radical 2)/(5-Radical 2) 3)describe the nature of the roots x^2-x-6=0 x^2+4x+29=0 4) Solve for x and check Radical (x^2 +4x +44) +3=2x I got 7 and -5/3 as answers, was not sure though
December 11, 2008
Question Details: A crate of mass1 on a frictionless inclined plane is attached to another crate, mass2 by a massless rope. The rope passes over an ideal pulley so the mass m2 is suspeneded in air. The plane is inclined at an angle 36.9. Use conservation of energy to find how ...
November 11, 2008
The rotor is an amusement park ride where people stand against the inside of a cylinder. Once the cylinder is spinning fast enough, the floor drops out. A-What force keeps the people from falling out the bottowm of the ride? I think that it's the Normal force? B-If the ...
October 21, 2008
Take the derivative of both sides of the equation implicitly: d/dx(xy^3+xy)=d/dx(14) y^3+3xy^2*y'+y+xy'=0 At x=7, y=1. Thus, 1^3+3(7)(1^2)*y'+1+7y'=0 which yields y'=-2/28=-1/14 The slope of the tangent line is m which also is y'. Thus, you now have m=-...
May 9, 2008
d/dx(4x^2+3x+xy)=d/dx(2) 8x+3+y+xy'=0 At x=2, y=-10, we get 16+3-10+2y'=0 Solving for y' yields y'(2)=-9/2. You are not suppose to plug in 2 for y. y(2)=-10 means that the function has a value of -10 when x=2.
May 9, 2008
the limit as x approaches 0 of (sinx/x) is 1. Hence, you need to get the given expression, sin3x/7x in the form sinu/u. Observe that sin3x/7x = (sin3x/3x)*(3x/7x)... multiply the numerator and denominator by 3x so we have the expression sinu/u. Thus, the limit as x approaches ...
May 8, 2008
Since the line is tangent at a point to the circle, then the point lies on the circle. Also, since you know the center, the radius is simply the distance between the points (0,0) and (3,4). a) So, radius=d=sqrt((3-0)^2+(4-0)^2)=5 b) x^2+y^2=25 c) Observe that the radius is ...
April 30, 2008
The equilibrium constant Kc equals 5.90 for the reaction CH3COOH + C2H5OH <==> CH3COOC2H5 + H2O Find the molar concentrations of acetic acid, ethanol, ethyl acetate, and water at equilibrium when .10 M acetic acid and .20 M ethanol are allowed to equilibrate. I started ...
April 16, 2007
Carbonyl fluoride, COF2, is an important intermediate for organic fluorine compounds. It can be prepared by the following reaction: CO2(g) + CF4(g) <==> 2COF2(g) At 1000*C, K for this reaction is .50. What are the partial pressures of all the gases at equilibrium when ...
April 15, 2007
2E-3= (19E-6)(2)(DeltaT) + (23E-6)(1)(DeltaT) Simplified equation: .002= (3.8E-5) (DeltaT) + (2.3E-5) (DeltaT) More simpllified: .002= (6.1E-5) (DeltaT) DeltaT= 32.7869 Answer: 32.7869 + 29 = 61.7869
April 14, 2007