A+ Answers

1) What is the minimum gauge pressure needed in the water pipe leading to a building if water is to come out of a faucet on the 12th floor, 41 m. above the pipe?

2) Estimate the pressure exerted on the floor by a 55 kg. store clerk standing momentarily on a single heel of their shoe, where the heel area = 8 cm2.

3) A 3 Kg. balloon is filled with 10 m3 of helium. How much force is needed to hold it down? (Don’t forget the weight of the balloon.)

 

4) The lift used in an automotive garage consists of a piston exerting a constant pressure of 200 kpa. (kilopascal) on a hydraulic reservoir. The output piston connected to the lift has a diameter of 40.0 cm. What is the maximum force that can be exerted by this lift ?

5) In 2012, the movie director James Cameron descended in a custom build submarine to a depth of 10,920 metres in the Pacific ocean near Guam into the Marianas Trench. Neglecting the increase in water density with depth:

 

  1. Find the increase in pressure on the Trieste at the bottom of its dive (assume the interior is maintained at normal surface atmospheric pressure).
  2. What is the pressure, at this depth, in atmospheres ?

6) A rectangular wooden draft 3m by 4m in size and of weight 10,000 N is floating in fresh water lake. What is the minimum depth of fresh water required to float this raft?

7) A water hose of internal diameter 12.5 mm is used to fill a bucket it is noted that 8L of fresh water (about 2 gallons) is collected in 1 minute.

  1. what is the volume equivalent of 8L expressed in m3 (cubed)? (5 points)
  2. What is the rate of flow expressed as m^3/s? (5 points)
  3. What is the velocity of water flow from the hose, expressed as m/s? (10 points)