Explain how an aeroplane gets lift.

Milk is ___ dense than the cream that floats on top. (3.7)

In the cartoon movie Pocahontas (https://openstaxcollege.org/I/2lpocahontclip) Pocahontas runs to the edge of a cliff and jumps off, showcasing the fun side of her personality. (a) If she is running at 3.0 m/s before jumping off the cliff and she hits the water at the bottom of the cliff at 20.0 m/s, how high is the cliff? Assume negligible air drag in this cartoon. (b) If she jumped off the same cliff from a standstill, how fast would she be falling right before she hit the water?

Why does atmospheric pressure decrease more rapidly than linearly with altitude?

The outward force on one end of an air tank was calculated in Example 11.2. How is this force balanced? (The tank does not accelerate, so the force must be balanced.)

You are applying for a position with a sea rescue unit and are taking the qualifying exam. One question on the exam is about the use of a diving bell. The diving bell is in the shape of a cylinder with a vertical length of L = 2.50 m. It is closed at the upper circular end and open at the lower circular end. The hell is lowered from air into seawater ( = 1.025 g/cm3) and kept in its upright orientation as it is lowered. The air in the bell is initially at temperature Ti = 20.0C. The bell, with two humans inside, is lowered to a depth (measured to the bottom of the bell) of 27.0 fathoms, or h = 49.4 m. At this depth the water temperature is Tf = 4.0C, and the bell is in thermal equilibrium with the water. The exam question asks you to compare two situations: (i) No additional gas is added to the interior of the bell as it is submerged. Therefore, water enters the open bottom of the bell and the volume of the enclosed air decreases. (ii) The bell is fitted with pressurized air tanks, which deliver high-pressure air into the interior of the bell to keep the level of water at the bottom edge of the bell. This choice requires money and effort to attach the tanks. The exam question asks: Which scenario is better?

An empty metal soap dish barely floats in water. A bar of Ivory soap floats in water. When the soap is stuck in the soap dish, the combination sinks. Explain why.

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 be gorge, the river narrows to 20-m wide and averages 20-m deep. (a) What be 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?

(a) Estimate the time it would take to a private swimming pool with a capacity of 80,000 L using a garden hose delivering 60 L/min. (b) How long would it take if you could divert a moderate size river, flowing at 5000 m3/s into pool?

Will the same ship float higher in salt water than in freshwater? Explain your answer.