The answer is 20. Frequency is "number of times" per unit time.
<span>A car with a mass of 1500kg starts from rest and accelerates to a speed of 18m/s in 12s. Assume that the force of resistance remains contant at 400N during</span>
Divide the flow rate (0.750 m³/s) by the cross-sectional area of each pipe:
diameter = 40 mm ==> area = <em>π</em> (0.04 m)² ≈ 0.00503 m²
diameter = 120 mm ==> area = <em>π</em> (0.12 m)² ≈ 0.0452 m²
Then the speed at the end of the 40 mm pipe is
(0.750 m³/s) / (0.00503 m²) ≈ 149.208 m/s ≈ 149 m/s
(0.750 m³/s) / (0.0452 m²) ≈ 16.579 m/s ≈ 16.6 m/s
<span>Well, ice is NOT more compressed than water.
Ice molecules do NOT have more charge than water molecules.
Water does NOT have a lower temperature than ice.
But water molecules DO move around more easily than ice molecules</span>
