Pls answer fast!
a girl throws a rock into a pond. a leaf floating ok the pond bobs up and down but does not change location on the ponds surface. why not?

a. the wave transports only energy, not matter.
b. the rock produced a stationary wave, not a moving wave
c. the rock was only a single disturbance, not a repeating motion.
d. the wave made by the rock is not strong enough to move the leaf

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.