Answer:
(A) Frictional force will be equal to 27.92 N
(B) Mass is equal to 33120 kg
Explanation:
(A) Diameter of nozzle d = 2.20 cm
So radius [tex]r=\frac{d}{2}=\frac{2.20}{2}=1.10cm[/tex]
eight h = 7.5 m
Density of water [tex]\rho =1000kg/m^3[/tex]
Acceleration due to gravity [tex]g=9.8m/sec^2[/tex]
Pressure on the rubber stopper
[tex]P=\rho hg[/tex]
[tex]p=1000\times 7.5\times 9.8=73500Pa[/tex]
Area of cross section [tex]A=\pi r^2[/tex]
[tex]A=3.14\times 0.01^2=3.799\times 10^{-4}m^2[/tex]
So force [tex]F=PA[/tex]
[tex]F=73500\times 3.799\times 10^{-4}=27.92N[/tex]
(B) Speed of the water through nozzle
[tex]v=\sqrt{2gh}[/tex]
[tex]=\sqrt{2\times 9.8\times 7.5}=12.12m/sec[/tex]
Volume of water flow
[tex]V=vA=12.12\times 3.799\times 10^{-4}=0.0046m^3/sec[/tex]
Mass of water flow per sec
[tex]m=\rho V=1000\times 0.0046=4.6kg[/tex]
Total time t = 2 hour = 2×3600 = 7200 sec
So total mass flow
[tex]m=4.6\times 7200=33120kg[/tex]
