Most popular questions and responses by Christ
  1. phy

    An electric kettle contains 1.5 kg of water at 100o C and powered by a 2.0 kW electric element. If the thermostat of the kettle fails to operate, approximately how long will it take for the kettle boil dry? (Take the specific latent heat of vaporization of

    asked on January 24, 2013
  2. Chem

    A water sample is suspected to be contaminated by iron (III) ions. How could you determine if the sample is really contaminated?

    asked on October 25, 2010
  3. phy

    Calculate the average translational kinetic energy of a nitrogen molecule at 27 degree celcius

    asked on January 24, 2013
  4. phy

    A piece of plastic barely floats in water. If it has a mass of 20g, what is its volume?

    asked on January 24, 2013

    A box is lifted with a pry bar, by slipping the bar under the box and lifting up on the bar. If the pry bar is 2m in length and it is grasped at the end, and the box is located at the opposite end, the fulcrum, with its center of gravity at a distance of

    asked on March 7, 2011
  6. phy

    At what temperature will the root-mean-square speed of oxygen molecules have the value of 640 m/s? 1 kilomole of oxygen has a mass of 32kg.

    asked on January 24, 2013
  7. phy

    1 What is the gravitational field strength at a height h above the surface of the Earth? R is the radius of the earth gR2(R+h)2 gR(R+h) Rg(R−h) R2g(R−h)2 2 The instrument used for experimental determination of the value of the universal gravitational

    asked on January 28, 2013
  8. phy

    1 An object is thrown upward from the edge of a tall building with a velocity of 10 m/s. Where will the object be 3 s after it is thrown? Take g=10ms−2 15 m above the top of the building 30 m below the top of the building 15 m below the top of the

    asked on January 28, 2013
  9. phy

    1 Physical quantities such as length, mass, time and temperature are referred to as vector quantities fundamental quantities scalar quantities derived quantities 2 The following are examples of vector quantities except displacment velocity accleration

    asked on January 28, 2013
  10. phy

    A 0.5kg piece of metal (c = 600/kgK) at 300 degree celcius is dumped into a large pool of water at 20 degrees celcius. Assuming the change in temperature of water to be negligible, calculate the overall change in entropy for the system

    asked on January 24, 2013
  11. phy

    Calculate the electric power which must be supplied to the filament of of a light bulb operating at 3000K. The total surface area of the filament is 8×10−6m2 and its emissivity is 0.92.

    asked on January 24, 2013
  12. Physics

    Paul and john have the same mass of 50kg.They both climbed a stairof height 5 meters. Paul climbed the stair in 10 seconds while john climbed the same stair in 15 seconds. Which of them performed greater work? Which of them has more power?

    asked on August 16, 2017
  13. Science

    Lead(ll) Iodide can be produced from the reaction of Lead(ll) nitrate and potassium Iodide.What mass of lead(ll) iodide is produced when 50.0 mL of each solution is combined,forming a 0.750 M Solution of potassium nitrate? Please help me to solve this

    asked on February 15, 2017
  14. phy

    An engine absorbs 2000J of heat from a hot reservoir and expels 750J to a cold reservoir during each operating cycle. What is the power output of the engine if each cycle lasts for 0.5 seconds?

    asked on January 24, 2013
  15. grammar

    Label each clause subordinate or independent. 1. If you visit the city of Chicago.subordinate 2.the Art Institute of Chicago is quite famous independent 3.While the Chicago White Sox play in Comiskey Park. subordinate 4.after the sears Tower was built

    asked on November 8, 2009
  16. phy

    If a force of 80N extends a spring of natural length 8m by 0.4m what will be the length of the spring when the applied force is 100N

    asked on January 24, 2013
  17. Spanish

    We have to translate the following sentences into spanish [we're working on subjunctive -- adverbial clauses.] He will insist until she accepts. My answer: Insistirá hasta que acepte. Is this right? I know insistir often carries along "en", but it doesn't

    asked on January 31, 2007
  18. phy

    Calculate the change in internal energy of 2kg of water at 90 degree Celsius when it is changed to 3.30m3 of steam at 100oC . The whole process occurs at atmospheric pressure. The latent heat of vaporization of water is 2.26×106J/kg

    asked on January 24, 2013
  19. english

    Identifying the subordinate clauses.then write Noun,adjective, or adverb to tell what kind of clause it is. 1-Elizabeth Kenny was a nurse who treated polio patients. answer: who treated polio patients. its an adverb clause. 2-Whoever broke the window will

    asked on November 12, 2009
  20. grammar

    Tell if the sentences, are phrase write phrase if it is a clause, write independent or subordinate. 9 Before settlers arrived .(phrase) 10 In 1794 .(phrase) 11 When it became a city .(subordinate) 12 Chicago had its first railroad.(independent) 13 Before

    asked on November 8, 2009
  21. Science

    How many grams of ammonium nitrate nedd to be added to 500g of water so that the freezing point becomes -8.3 °C?

    asked on February 14, 2017
  22. phy

    A passenger in a moving car and a passerby standing at the road side see each other as moving in the opposite direction. Which of the following is NOT true? The passenger is in motion relative to the passer-by The passer-by is stationary relative to the

    asked on January 28, 2013
  23. phy

    Tinny insects such as mosquitoes can seat on the surface of water. Which physical principle makes this possible?

    asked on January 24, 2013
  24. phy

    A string of natural length L extends to a new length L' under tensile force F. If Hooke’S law applies, the work done in stretching the spring is ------------

    asked on January 24, 2013
  25. math equation

    Is the answer for this equation: 4+8[9/3(9-6)] = 12

    asked on January 4, 2010
  26. grammar/Ms Sue

    14 during the great fire (independent 15 After industries were rebuilt(subordinate

    asked on November 8, 2009
  27. math/equation/Paul

    I meant is 12 the correct answer to the equation 4+8[9/3(9-6)]

    asked on January 4, 2010


    asked on November 12, 2009
  1. Physics


    posted on September 27, 2018
  2. Science

    Can you please give me the formula

    posted on February 15, 2017