Physics

posted by .

To suck water up a straw to a maximum height of 68 mm, what minimum gauge pressure must be produced in the lungs? Note that in order to be able to suck up water, the pressure in the lungs must be lower than the pressure outside by the exact amount of pressure created by the weight of the column of water in the straw.

  • Physics -

    68 mm = 0.068 m

    P= pgd (where p=density)
    P= (1000 kg/m^3)g(0.068 m)
    P= 666 Pa

    and it's negative, I don't know why.

    Is this for UTSC? I have the same question, exact wording :D

  • Physics -

    It is negative because gauge pressures are measured relative to atmospheric pressure. It has to be negative to suck water up the straw.

    See
    http://www.jiskha.com/display.cgi?id=1259197828
    for a similar response.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics

    The highest that George can suck water up a very long straw is 2.0 m. (This is a typical value.) What is the lowest pressure that he can maintain in his mouth?
  2. Physics

    To suck water up a straw to a maximum height of 187 mm, what minimum gauge pressure must be produced in the lungs?
  3. Physics

    To suck water up a straw to a maximum height of 98 mm, what minimum gauge pressure must be produced in the lungs?
  4. physics

    The highest George can suck water up a very long straw is 2.0m What is the lowest pressure he can maintain in his mouth?
  5. Physics

    Suppose you have a very long straw that can reach from a cup of water on the ground level to the top of a very tall building. When you use a pump to suck on the straw in order to bring water up, a. you can bring the water up to any …
  6. Physics

    Suppose you have a very long straw that can reach from a cup of water on the ground level to the top of a very tall building. When you use a pump to suck on the straw in order to bring water up, a. you can bring the water up to any …
  7. physics

    The human lungs can function satisfactorily up to a limit where the pressure difference between the outside and inside of the lungs is 1/21 of an atmosphere. If a diver uses a snorkel for breathing, how far below the water can she …
  8. Physics

    The human lungs can function satisfactorily up to a limit where the pressure difference between the outside and inside of the lungs is 1/21 of an atmosphere. If a diver uses a snorkel for breathing, how far below the water can she …
  9. physics

    The human lungs can function satisfactorily up to a limit where the pressure difference between the outside and inside of the lungs is 1/21 of an atmosphere. If a diver uses a snorkel for breathing, how far below the water can she …
  10. Math

    When at rest an average adult breathes in and out every 4s. the average minimum amount of air the lungs is 0.08L and the average maximum amount of air in the lungs is 0.82L. Assume the lungs have a minimum amount of air at t=0 where …

More Similar Questions