Author Question: Water circulates in a thermosiphon, hot water system because ________. a. a pump is used b. ... (Read 28 times)

pragya sharda · **on:** Jul 28, 2018

Water circulates in a thermosiphon, hot water system because ________.
a. a pump is used
b. gravity causes water to flow from the top of the collector to the bottom
c. hot water is less dense than cold water
d. solar energy is used to run the circulating pump

Question 2

A uniform ladder 15 ft long is leaning against a frictionless wall at an angle of 53 above the horizontal. The weight of the ladder is 30 pounds. A 75-lb boy climbs 6.0-ft up the ladder. What is the magnitude of the friction force exerted on the ladder by the floor?
a. 43 lb
b. 34 lb
c. 38 lb
d. 47 lb
e. 24 lb