Fluid Statics & Dynamics Review

Gold is sold by the troy ounce (31.103 g). What is the volume of 1 troy ounce of pure gold? (The density of gold is 19.32 g/cm³)

• 1.61 cm^3

• 2.83 cm^3

• 3.66 cm^3

• 4.07 cm^3

A container has a cross-sectional area of 0.0625 m². What is the minimum height required for the container to hold 20 liters (0.02 m³) of water?

• 0.3 m

• 3.3 m

• 300 m

• 2 m

Mercury is supplied in flasks with 34.5 kg (about 76 lb). What is the volume in liters of this much mercury? Density of mercury is 13.6 kg/L.

• 2.54 liters

• 3.41 liters

• 7.37 liters

• 8.43 liters

A straightforward method of finding the density of an object is to measure its mass and then measure its volume by submerging it in a graduated cylinder. What is the density of a 240-g rock that displaces 89 cm³ of water?

• 2.7 g/cm³

• 3.0 g/cm³

• 2.5 g/cm³

• 2.9 g/cm³

The pressure exerted by a phonograph needle on a record is surprisingly large. If the equivalent of 1.00 g is supported by a needle, the tip of which is a circle 0.200 mm in radius, what pressure is exerted on the record in N/m²?

A submarine is stranded on the bottom of the ocean with its hatch 25.0 m below the surface. Calculate the force needed to open the hatch from the inside, given it is circular and 0.450 m in diameter. Air pressure inside the submarine is 1.00 atm.

• 39,900 N

• 11,500 N

• 57,750 N

• None of the above

What fraction of ice is submerged when it floats in freshwater, given the density of water at 0°C is very close to 1000 kg/m³? The density of ice is 917 kg/m³.

• 0.917

• 0.9

• 0.1

• 0.083

Logs sometimes float vertically in a lake because one end has become water-logged and denser than the other. What is the average density of a uniform-diameter log that floats with 20.0% of its length above water?

• 0.8 times the density of water

• 0.2 times the density of water

• 1.2 times the density of water

• Cannot be determined

The Huka Falls on the Waikato River is one of New Zealand's most visited natural tourist attractions. On average the river has a flow rate of about 300,000 L/s. At the gorge, the river narrows to 20 m wide and averages 20 m deep. (a) What is the average speed of the river in the gorge? (b) What is the average speed of the water in the river downstream of the falls when it widens to 60 m and its depth increases to an average of 40 m?

Water is moving at a velocity of 2.00 m/s through a hose with an internal diameter of 1.60 cm. (a) What is the flow rate in liters per second? (b) The fluid velocity in this hose's nozzle is 15.0 m/s. What is the nozzle's inside diameter?

• 0.4 L/s and 0.58 cm

• 0.4 L/s and 0.64 cm

• 0.3 L/s and 0.60 cm

• 0.2 L/s and 0.56 cm