Explanation:
The given data is as follows.
Fluid is water so, density 
Weight flow rate = 500 lbf/s = 2224.11 N/sec
Cross-sectional area (A) = 
= 0.05184 
Hence, weight flow rate will be given as follows.
w = 
2224.11 N/sec = 
V =
m/s
= 4.373 m/s
Thus, we can conclude that average velocity in the given case is 4.373 m/s.
The ideal mechanical advantage of the pulley system is 3
Explanation:
The speed of a wave is given by :
......(1)
(i) Here, the wavelength of a sound wave in air reduces by a factor of 3. Equation (1) becomes :

Wavelength and frequency are inversely proportional to each other. So, if wavelength of a sound wave in air reduces by a factor of 3, then the frequency will increases by a factor of 3.
(ii) It remains the same.

= Joules ÷ (0.5×Kilograms)
14J ÷ 8.5 = 1.64705882
Remember, 1.64705882 = v², so we need to find the square root.
The square root of 1.64705882 is 1.283377894464448
Hope this helps!