CRITICAL THINKING 10 points for best answer plz!?

That depends entirely on the difference in area between the two spigots. Volume flowrate = Q = v*A where v is speed of water and A is area of the spigot. If the question assumes constant volume flow rate (i.e. the spigot is 1/2 the area of the first but the speed doubles) it would take the same amount of time. but without knowing the relative areas of the problem you can't get an exact answer. symbolically

first spigot:

Volume = v1*A1*t = v1*A1*30

Second spigot

Volume = v2*A2*t2 = 2*v1*A2*t2

so... because the volume of the glass doesn't change:

30*A1*v1 = 2*v1*A2*t2

cancel v1 terms and divide through by 2*A2

t2 = 15* (A1 / A2)

in seconds

Edit:

I worked assuming that there was a mechanism to double the speed. Otherwise OldPilot is right.

Old Hydraulic Engineering trick:

The velocity of the water is equal to the velocity of an object falling the depth of the water.

Therefore, the question is wrong. You cannot double the speed by changing the nozzle. The pressure at the nozzle is a constant (large container), thus the driving force is a constant, thus by F = MA the acceleration per unit mass is a constant, thus the speed is a constant.

So velocity is a constant, so long as depth does NOT change.

Volume/unit time = Area * Velocity

Question cannot be answered, it is based on a false premise

If your teacher doubts this, do the experiment. Get a large container (5 gallon gas can) fill it with water, leave the top open,and poke a hole and trace the parabola of the stream of water. Do it again with a larger hole, you will get the same parabola so long as the hole is small enough that the water level in the container does not significantly change during the experiment.

Wouldn't it take the same amount of time? The speed of the water leaving the spigot may change but the volume per time of water leaving the spigot may not change...

Conservation of mass.

The pressure forces the same amount of water thru the opening, regardless.

The water may speed up, but less is getting thru. Open the spigot WIDE open, the speed of the water is slower, but more water is coming out......all takes the same amount of time.