Questions from College Physics

Q: Suppose two worlds, each having mass M and radius R,

Suppose two worlds, each having mass M and radius R, coalesce into a single world. Due to gravitational contraction, the combined world has a radius of only ¾ R. What is the average density of the com...

Q: In most species of clingfish (family Gobiesocidae), pelvic and pectoral

In most species of clingfish (family Gobiesocidae), pelvic and pectoral fins converge to form a suction cup edged by hairy structures that allow a good seal even on rough surfaces. Experiments have sh...

Q: Take the density of blood to be p and the distance between

Take the density of blood to be p and the distance between the feet and the heart to be hH. Ignore the flow of blood. (a) Show that the difference in blood pressure between the feet and the heart is g...

Q: A worker applies a torque to a nut with a wrench 0

A worker applies a torque to a nut with a wrench 0.500 m long. Because of the cramped space, she must exert a force upward at an angle of 60.0° with respect to a line from the nut through the end of t...

Q: The approximate diameter of the aorta is 0.50 cm;

The approximate diameter of the aorta is 0.50 cm; that of a capillary is 10. mm. The approximate average blood flow speed is 1.0 m/s in the aorta and 1.0 cm/s in the capillaries. If all the blood in t...

Q: Superman attempts to drink water through a very long vertical straw as

Superman attempts to drink water through a very long vertical straw as in Figure P9.82. With his great strength, he achieves maximum possible suction. The walls of the straw don’t co...

Q: The human brain and spinal cord are immersed in the cerebrospinal fluid

The human brain and spinal cord are immersed in the cerebrospinal fluid. The fluid is normally continuous between the cranial and spinal cavities and exerts a pressure of 100 to 200 mm of H2O above th...

Q: A hydrometer is an instrument used to determine liquid density. A

A hydrometer is an instrument used to determine liquid density. A simple one is sketched in Figure P9.84. The bulb of a syringe is squeezed and released to lift a sample of the liquid of interest into...

Q: Figure P9.85 shows a water tank with a valve.

Figure P9.85 shows a water tank with a valve. If the valve is opened, what is the maximum height attained by the stream of water coming out of the right side of the tank? Assume h = 10.0 m, L = 2.00 m...

Q: A helium-filled balloon, whose envelope has a mass of

A helium-filled balloon, whose envelope has a mass of 0.25 kg, is tied to a 2.0-m-long, 0.050-kg string. The balloon is spherical with a radius of 0.40 m. When released, it lifts a length h of the str...