Final answer:
The speed of water coming out of the hose can be calculated using the formula v = Q/A. When the diameter of the hose opening is halved, the speed is increased by a factor of 4.
Step-by-step explanation:
The speed of the water coming out of the hose can be calculated using the formula v = Q/A, where v is the speed, Q is the volume flow rate, and A is the cross-sectional area of the hose opening.
To find the volume flow rate, we can convert the volume of the bucket to cubic meters (1 gallon = 0.00378 m^3) and divide it by the time taken to fill the bucket (60 seconds).
When the diameter of the hose opening is halved, the area is reduced by a factor of 4, and therefore the speed is increased by a factor of 4.