• Your friend fills his canteen from a stream and adds some Cl tablets to disinfect the water.?

    A few days later he develops a serious case of diarrhea. He goes to the doctor and is told that he does not have a viral infection. What would you suspect to be the cause of his diarrhea? What would have been a more effective way to disinfect the water?
    A few days later he develops a serious case of diarrhea. He goes to the doctor and is told that he does not have a viral infection. What would you suspect to be the cause of his diarrhea? What would have been a more effective way to disinfect the water?
    Infectious Diseases · 1 week ago
  • Wastewater treatment: If you were a consultant to the city, which option would you recommend that they take and why?

    The effluent from a wastewater treatment plant is being discharged into a lake, and because of that fact the lake is experiencing serious cultural eutrophication problems. The city operating the plant is considering two alternative forms of tertiary nutrient removal, the first of which would reduce the N concentration in the effluent to 1 ppm and... show more
    The effluent from a wastewater treatment plant is being discharged into a lake, and because of that fact the lake is experiencing serious cultural eutrophication problems. The city operating the plant is considering two alternative forms of tertiary nutrient removal, the first of which would reduce the N concentration in the effluent to 1 ppm and the second of which would reduce the P concentration in the effluent to 1 ppm. Both options cost exactly the same amount of money. The city can afford only one of the options.
    Earth Sciences & Geology · 1 week ago
  • Which sedimentation basin do you think will do a better job of minimizing nonpoint source pollution and why?

    A contractor is hired to build a condominium on a parcel of land with an area of 4 hectares. In an effort to minimize runoff from the construction site, the contractor builds a sedimentation basin with a depth of 3 meters and an area of 400 m^2. At the same time a nearby town decides to build a sedimentation basin to intercept runoff from the town... show more
    A contractor is hired to build a condominium on a parcel of land with an area of 4 hectares. In an effort to minimize runoff from the construction site, the contractor builds a sedimentation basin with a depth of 3 meters and an area of 400 m^2. At the same time a nearby town decides to build a sedimentation basin to intercept runoff from the town that is polluting a recreational lake. The town occupies an area of 250 hectares. About 50 percent of the town consists of impervious surfaces such as streets, parking lots, and roof tops. The town builds a sedimentation basin with a depth of 3 meters and an area of 4,000 m^2.
    2 answers · Earth Sciences & Geology · 1 week ago
  • What will happen to algae biomass if Phosphorus in the wastewater is reduced by a factor of 10? Increased by a factor of 10?

    Wastewater with a N/P ratio of 8 is being discharged into a lake with algae needing a N/P ratio of 16. Use Redfield ratio I think N would increase by a factor of 10 and decrease by a factor of 2, but I'm trying to figure out P. Would it be reduced and increased by 5? Want to make sure I'm doing this right!
    Wastewater with a N/P ratio of 8 is being discharged into a lake with algae needing a N/P ratio of 16. Use Redfield ratio I think N would increase by a factor of 10 and decrease by a factor of 2, but I'm trying to figure out P. Would it be reduced and increased by 5? Want to make sure I'm doing this right!
    Earth Sciences & Geology · 4 weeks ago
  • What is the optical depth associated with the eutrophic zone?

    Given equation: ln(Io/I) I=irradiance at particular depth Io=irradiance at surface Base eutrophic zone is the depth at which I=1 percent of Io Can someone explain to me how to go about solving this question? I've only ever done it with actual values for I and Io.
    Given equation: ln(Io/I) I=irradiance at particular depth Io=irradiance at surface Base eutrophic zone is the depth at which I=1 percent of Io Can someone explain to me how to go about solving this question? I've only ever done it with actual values for I and Io.
    1 answer · Physics · 4 weeks ago
  • What will happen to algae biomass if Phosphorus in the wastewater is reduced by a factor of 10? Increased by a factor of 10?

    Wastewater with a N/P ratio of 8 is being discharged into a lake with algae needing a N/P ratio of 16. Use Redfield ratio I think N would increase by a factor of 10 and decrease by a factor of 2, but I'm trying to figure out P. Would it be reduced and increased by 5? Want to make sure I'm doing this right!
    Wastewater with a N/P ratio of 8 is being discharged into a lake with algae needing a N/P ratio of 16. Use Redfield ratio I think N would increase by a factor of 10 and decrease by a factor of 2, but I'm trying to figure out P. Would it be reduced and increased by 5? Want to make sure I'm doing this right!
    Chemistry · 4 weeks ago
  • What is the unstrained length of the cord?

    A 7.2-kg bowling ball is attached to the end of a nylon cord with a cross-sectional area of 3.75 x10^-5 m2. The other end of the cord is fixed to the ceiling. When the bowling ball is pulled to one side and released from rest, it swings downward in a circular arc. At the instant it reaches its lowest point, the bowling ball is 1.6 m lower than the... show more
    A 7.2-kg bowling ball is attached to the end of a nylon cord with a cross-sectional area of 3.75 x10^-5 m2. The other end of the cord is fixed to the ceiling. When the bowling ball is pulled to one side and released from rest, it swings downward in a circular arc. At the instant it reaches its lowest point, the bowling ball is 1.6 m lower than the point it was released from, and the cord is stretched 2.51 x10^-3 m from its unstrained length. What is the unstrained length of the cord? Hint: When calculating any quantity other than the strain, ignore the increase in the length of the cord.
    1 answer · Physics · 11 months ago
  • If the skier's acceleration up the slope has a magnitude of 0.9 m/s2, what is the original (unstretched) length of the cable?

    A 57-kg snow skier is being pulled up a 13° slope by a steel cable. The cable has a cross-sectional area of 7.23x10^-5 m2. The cable applies a force to the skier, and, in doing so, the cable stretches by 2.04 x10^-4 m. A frictional force of magnitude 62 N acts on the skis and is directed opposite to the skier's motion.
    A 57-kg snow skier is being pulled up a 13° slope by a steel cable. The cable has a cross-sectional area of 7.23x10^-5 m2. The cable applies a force to the skier, and, in doing so, the cable stretches by 2.04 x10^-4 m. A frictional force of magnitude 62 N acts on the skis and is directed opposite to the skier's motion.
    1 answer · Physics · 11 months ago
  • What is the radius of the wire at the same strain as the spider's thread, when the thread is stressed by the full weight of the spider?

    A 9.00x10^-4kg spider is hanging vertically by a thread that has a Young's modulus of 1.20x10^8 N/m^2 and a radius of 1.50x10^-5 m. Suppose that a 87-kg person is hanging vertically on an aluminum wire.
    A 9.00x10^-4kg spider is hanging vertically by a thread that has a Young's modulus of 1.20x10^8 N/m^2 and a radius of 1.50x10^-5 m. Suppose that a 87-kg person is hanging vertically on an aluminum wire.
    1 answer · Physics · 11 months ago
  • Find the tension in the wire when the tuning peg is turned through two revolutions.?

    One end of a piano wire is wrapped around a cylindrical tuning peg and the other end is fixed in place. The tuning peg is turned so as to stretch the wire. The piano wire is made from steel (Y = 2.0x10^11 N/m^2). It has a radius of 0.76 mm and an unstrained length of 0.81 m. The radius of the tuning peg is 2.0 mm. Initially, there is no tension in... show more
    One end of a piano wire is wrapped around a cylindrical tuning peg and the other end is fixed in place. The tuning peg is turned so as to stretch the wire. The piano wire is made from steel (Y = 2.0x10^11 N/m^2). It has a radius of 0.76 mm and an unstrained length of 0.81 m. The radius of the tuning peg is 2.0 mm. Initially, there is no tension in the wire, but when the tuning peg is turned, tension develops. Find the tension in the wire when the tuning peg is turned through two revolutions. Ignore the radius of the wire compared to the radius of the tuning peg.
    1 answer · Physics · 11 months ago
  • Find the magnitude and direction of the sum of momenta of the two joggers.?

    An 85-kg jogger is heading due east at a speed of 1.5 m/s. A 55-kg jogger is heading 32° north of east at a speed of 3.8 m/s. Find the magnitude and direction of the sum of momenta of the two joggers. The magnitude is 328.4, but I can't get the angle correct for some reason! Please Help!
    An 85-kg jogger is heading due east at a speed of 1.5 m/s. A 55-kg jogger is heading 32° north of east at a speed of 3.8 m/s. Find the magnitude and direction of the sum of momenta of the two joggers. The magnitude is 328.4, but I can't get the angle correct for some reason! Please Help!
    2 answers · Physics · 1 year ago
  • How much work (in Joules) can a 3.0 hp lawnmower engine do in 1 hour? ?

    (1hp = 746 W and 1 h = 3600 s).  
    (1hp = 746 W and 1 h = 3600 s).  
    2 answers · Engineering · 1 year ago
  • At what height is its speed equal to v/2?

    A block slides down a smooth ramp, starting from rest at a height h. When it reaches the bottom, it’s moving at speed v. It then continues to slide up a second smooth ramp. At what height is its speed equal to v/2?
    A block slides down a smooth ramp, starting from rest at a height h. When it reaches the bottom, it’s moving at speed v. It then continues to slide up a second smooth ramp. At what height is its speed equal to v/2?
    1 answer · Physics · 1 year ago
  • What is the speed at which the satellite travels?

    A satellite is in a circular orbit about the earth (ME = 5.98E24 kg). The period of the satellite is 4.20E4s.
    A satellite is in a circular orbit about the earth (ME = 5.98E24 kg). The period of the satellite is 4.20E4s.
    2 answers · Physics · 1 year ago
  • Is the upward force of a seat at the top of a ferris wheel greater less or equal to the passenger's weight?

    At the top of a Ferris wheel, is the upward force the seat applies to the passenger greater than, less than, or equal to the passenger’s weight? Explain. 
    At the top of a Ferris wheel, is the upward force the seat applies to the passenger greater than, less than, or equal to the passenger’s weight? Explain. 
    8 answers · Physics · 1 year ago
  • What would be the satellites's orbital period?

    A satellite with mass (m) has a period of orbital (p) when it is in a circular orbit of radius (r) around a planet. If the satellite instead had a mass of 3m, what would be its orbital period? Answer in terms of p
    A satellite with mass (m) has a period of orbital (p) when it is in a circular orbit of radius (r) around a planet. If the satellite instead had a mass of 3m, what would be its orbital period? Answer in terms of p
    1 answer · Physics · 1 year ago