Avillage maintains a large tank with open top with water. the water can drain out of the tank through a hose of diameter 6.60 cm. the hose ends with a nozzle of diameter 2.20 cm. a rubber stopper is inserted in the nozzle. the water level in the tank is kept 7.50 m above the nozzle. (a) calculate the frictional force exerted by the nozzle on the stopper. (b) the stopper is removed. what mass of water flows from the nozzle in 2 hr?

Explain why electric current cannot exist if a current doesn't have a voltage source.

Asilver dollar is dropped from the top of a building that is 1324 feet tall. use the position function below for free-falling objects. s(t) = −16t2 + v0t + s0 (a) determine the position and velocity functions for the coin. s(t) = v(t) = (b) determine the average velocity on the interval [1, 2]. ft/s (c) find the instantaneous velocities when t = 1 second and t = 2 seconds. v(1) = ft/s v(2) = ft/s (d) find the time required for the coin to reach the ground level. (round your answer to three decimal places.) t = s (e) find the velocity of the coin at impact. (round your answer to three decimal places.) ft/s

Suppose that three astronomical objects, 1, 2, and 3 are observed to lie on a line, and the distance from object 1 to object 3 is d. object 1 has four times the mass of object 3, and seven times the mass of object 2. find the distance between objects 1 and 2 for which the net force on object 2 is zero.