density of water = 
velocity of flow = 
radius of pipe = 
Height of second floor = 
Now we can use here Bernuoli's Equation to find the speed of water flow at second floor



Now in order to find the radius of pipe we can use equation of continuity



So radius of pipe at second floor is 0.034 meter
Answer:
The correct answer is A. The sun is the energy source of the surface currents in the ocean
A magnetic field is a force field, invisibly pushing electrically charged objects just as a gravitational field pulls objects with mass. Whereas all objects with mass exert a gravitational field, however, not all objects have a magnetic field. Magnetic fields are created by electrical charges. Thanks to their structure at the atomic level, some substances -- like the iron in magnets -- have a permanent magnetic field.