Posts by P
Total # Posts: 290
Compounds with high melting points have ___ a. Covalent bonds b. Metallic Bonds c. Ionic bonds*** d. No chemical bonds How could you determine if a sample of gold is pure? Compare the sample's density with that of pure gold.*** Compare the sample's color with that of ...
September 29, 2016
You push a skateboard so that it rolls down the road at a speed of 1.40 m/s. You run after the skateboard at a speed of 3.80 m/s and while still behind the skateboard you jump off the ground at an angle of 30.0° above the horizontal hoping to land on the skateboard. How ...
September 22, 2016
You are thinking about taking gymnastics, so you go to the facility and get an idea of what to expect by looking out from the viewing room. The viewing room window is 4.40 m above the trampoline directly below, so it is perfect for viewing the the facility. Occasionally ...
September 17, 2016
Carmen rides her bicycle at a constant rate to the market. When she rides her bicycle back home along the same route, she bikes at three-quarters the rate she biked to the market. At any given time, t, the distance biked can be calculated using the formula d = rt, where d ...
August 29, 2016
A mineral sample is analyzed for its cobalt and calcium content. A sample is dissolved, and then the cobalt and calcium are precipitated as Co(OH)2(s) and Ca(OH)2(s). At what pH can Co(OH)2(s) be separated from Ca(OH)2(s) at 25 °C? Assume that an effective separation ...
July 9, 2016
Jenny must sit four papers for an exam. The mean of the first three papers Jenny has sat is 72%. (a)If she wants to get an overall mean of at least 75%,what is the lowest mark she can get in her fourth paper? (b) What is the highest possible mean she can get over all four ...
April 26, 2016
A farmer has a herd of 100 cattle with an average weight of 500 lbs/cow. It costs 50 cents a day to keep each cattle. They are gaining weight at a rate of 6 lbs per day. The market price is now $1 per lb for beef and is falling by 1 cent each day. How long should the farmer ...
March 21, 2016
A car is initially travelling at 30 m/s, which is above the speed limit. The driver sees a speed limit trap ahead and applies the brakes for 5 seconds, causing the car to slow down by 2m/s every second while the brakes are on. How far does a car travel whilst the brakes ...
November 11, 2015
first u find how long AB is which is (16, 8) in length.... 10+6 = 16 and 6+2 = 8. 3/4 * 16 = 12 3/4 * 8 = 6 so starting on point A add (12, 6) to (-10,-6) you will get (2,0) because 12-10=2; 6-6=0
September 24, 2015
A car of mass 1060 kg is on an icy driveway inclined at an angle of 39◦ . The acceleration of gravity is 9.8 m/s 2 . θ If the incline is frictionless, what is the acceleration of the car? Answer in units of m/s 2
November 18, 2014
a photocopy store advertises the following prices: 5 cents per copy for the first 20 copies, 4 cents per copy for the 21st through 100th copy, and 3 cents per copy after the 100th copy. Let x be the # of copies, and let y = the total cost of the photocopying. find the equation...
September 7, 2014
A rowing team rowed 100 miles while going with the current in the same amount of time as it took to row 20 miles going against the current. The rate of the current was 6 miles per hour. Find the rate of the rowing team in still water.
April 2, 2014
Vanessa typically works 8 hours per day in a normal 5 day work week. Last week, however, Vanessa had to take 90 minutes off on Tuesday, 45 minutes off on Thursday, and she left two and a half hours early on Friday. How many hours did Vanessa work last week? (A.35 hours 15 ...
November 24, 2013
Company A rents copiers for a monthly charge of $200 and $0.08 per copy. Company B rent copiers for a monthly charge of $400 and $0.04 per copy. How many copies produce the same bill? The answer I have is 5,0000 is this correct? Thanks
November 10, 2013
A plane flies in a direction of N70°E for 80 km and then on a bearing of S10°W for 150 km. a How far is the plane from its starting point? b What direction is the plane from its starting point?
September 15, 2013
Recall that the average velocity between times t1and t2 is calculated using vave = y(t2) − y(t1)/t2 − t1. We are given that y = 14t − 1.86t^2. Evaluating at t = 1, we have y(1) = 14(1) − 1.86(1)2 = 12.14. Thus, the average velocity between times 1 and 1...
September 4, 2013
The electric and magnetic fields of a plane electromagnetic wave are given by the formulas below, where and are both in meters and is in seconds. This wave is traveling through a medium whose index of refraction is 1.3. Reminder: The "x.xxenn t" notation in the sine...
June 15, 2013
A circuit is composed of a capacitor C= 3 micro F, two resistors both with resistance 69 Ohm, an inductor 6.00e-2 H, a switch , and a battery 25 V. The internal resistance of the battery can be ignored . Reminder: The " L=x.xxenn H" notation means " L=x.xx X 10...
June 15, 2013
Please give ans for Q5 for values I am getting them last chance please What is the total magnetic flux through the loop (in Tesla m ) when is 62 cm. Include only the magnetic flux associated with the external field (i.e. ignore the flux associated with the magnetic self-field ...
June 15, 2013
This wave is traveling through a medium whose index of refraction is 1.3. E= 2.8 xsin(2*π/lamdaz + 1.19e16) t V/m B =B_0sin(2*π/lamdaz + 1.19e16 t) Tesla Please tel ans for this phy.
June 14, 2013
All answers should be in degrees. (a) Using the result of Lecture 31 Question 3, and Snell's law, derive and evaluate for the secondary rainbow for the following values of the incidence angle and index of refraction . 1 , 1.4 incorrect 45 , 1.3 incorrect 87 , 1.55 ...
June 5, 2013
hmmmm pls. post ans for this question pls I have got only one chance left. A solenoid has N=1863.0 turns, length d=46 cm , and radius b=0.4 cm, (b<<d) . The solenoid is connected via a switch, S1 , to an ideal voltage source with electromotive force ϵ=3 V and a ...
May 22, 2013
hmmmm pls. find ans of the below. An electromagnet has a steel core (κM≈ 2500) with an approximately circular cross sectional area of 5.0 cm2. The radius of the magnet is 10.0 cm; there is a small air gap of only 2.6 mm (see sketch). The current through the magnet...
May 22, 2013
Consider the LR circuit. We have R1=9 Ohms, R2=5 Ohms, R3=19 Ohms, V=2 Volts, L=0.09 H. L and R2 are connected in series, Combination of L and R2 in series is connected with R3 in parallel. This whole combination is connected in series with R1 and voltage source and switch. At...
April 17, 2013
A circuit consists of 5 resistors and 3 batteries (see diagram); the connecting wires have all a negligible resistance. The values for R1 , R2 , R3 , R4 , and R5 are 14 Ω, 41 Ω, 68 Ω, 83 Ω, and 110 Ωrespectively. The batteries have a negligible ...
March 13, 2013
Three conducting straight wires (though insulated from each other) are each 2 m long. They are electrically connected to each other only at their ends points A and B. AB = 2 meter. The wires are cylindrical. One is made of copper, one of aluminum and one of iron. Their radii ...
March 13, 2013