A mercury barometer with a uniform tube has a length of 800mm above the mercury level in the trough. The barometer reads 740mm on a day when the actual atmospheric pressure is 769mmHg. Prove that the actual atmosphere pressure is 747mmHg on a day when this faulty barometer reads 730mm. Assume the temperature on both days is the same.

Awind turbine is rotating counterclockwise at 0.5 rev/s and slows to a stop in 10 s. its blades are 20 m in length. (a) what is the angular acceleration of the turbine? (b) what is the centripetal acceleration of the tip of the blades at t=0s? (c) what is the magnitude and direction of the total linear acceleration of the tip of the blades at t=0s?