Mohammed listed the steps that occur when a solar cell generates electricity.
1: Solar energy is absorbed by the cell.
2: Free electrons move to the front of the cell.
3: Electrons begin to move.
4: Electrons flow as electricity.
Which best explains how to correct Mohammed's error?
Switch steps 2 and 3.
Switch steps 3 and 4.
Move step 1 to appear after step 4.
Move step 4 to appear after step 1.

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.