Which of the following statements about gravitational potential energy is not true?
a. its magnitude is related to the work done by lifting an object.

b it depends on the choice of a coordinate system.

c. it is equal to the force required to move an object times the distance it is moved.

d. it is equal to the kinetic energy of the falling object at y = 0.

Consider a one meter long horizontal pipe with a constant 100 cm^2 cross sectional area. water flows rightward into the pipe at x = 0 with flow velocity 02m/sec at every point within the pipe intake area. at x=1, the rightward flow rate is 0.192 m/sec. assume the water is a conserved quantity in the pipe, so there must be a leak (a sink) somewhere in the pipe. 1. compute net volumetric flow of the source if the system to be in equilibrium. 2. now assume the pipe in the problem has no leaks. compute the net volumetric rate of change for the system.

Ihave this 50 question test the layer of earth's atmosphere where atoms and molecules escape into space is referred to as the a) exosphere b) ionosphere. c) mesosphere d) thermosphere

Which statement describes the formation of our sun? a disk formed of long trails of stars coiled into a spiral. it formed an elliptical flattened disk. heat and gases contracted within a nebula. gravity pushed stars away from a center core.