Final answer:
The best reason for regularly removing and reloading fire hoses is to maintain their integrity and prevent degradation. Calculating the fluid speed involves finding the cross-sectional area and then using the flow rate to find the velocity. The type of liquid, whether salt water or fresh water, does not affect the fluid speed calculation.
Step-by-step explanation:
The best reason for fire hoses to be removed and reloaded on an apparatus at least once every 30 days is to ensure the integrity of the hose and to prevent damage or degradation from factors such as mildew and mold. Regular maintenance also allows firefighters to inspect the hoses for any wear and tear that could compromise their performance during an emergency situation.
Calculating Fluid Speed and Flow Rate
To calculate the fluid speed in a fire hose with a 9.00-cm diameter carrying 80.0 L of water per second, we can use the formula for the flow rate which is Q= A*v, where Q is the flow rate, A is the cross-sectional area of the hose, and v is the fluid speed. Since Q = 80.0 L/s, which can be converted into cubic meters per second (m³/s) as 0.080 m³/s, we find the area (A) of the hose's inner cross-section and solve for v.
First, convert the diameter to meters: 9 cm = 0.09 m.
Then, calculate the area (A): A = π * (0.09 m / 2)^2.
Finally, solve for v: v = Q / A.
Answering part (c), the speeds would not be different if salt water replaced the fresh water in the fire hose since the calculation for speed is dependent on flow rate and cross-sectional area, not the type of the fluid.