~ Nature's Kiam Cai Blog ~
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ask lohOriginally posted by jay_rocks:x2.
poon boi, i wan to ask u a qn on rate of change, budden got diagram. -
lebbrel up
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diagram lehOriginally posted by poon cho tang:ask loh -
u put here, wait ltr then i cum backOriginally posted by jay_rocks:x2.
poon boi, i wan to ask u a qn on rate of change, budden got diagram.
ciaoz -
scan?Originally posted by jay_rocks:diagram leh -
diagram shows a vertical cross-section of a cointainer in the form of an inverted cone of height 60cm and base radius 20cm. the circular base is held horizontal and uppermost. water is poured into the container at a constant rate of 40cm³/s.
i) show tt, when depth of water in the container is x cm, the volume of water in the container is piex³/27 cm³
II)find rate of increase of x at the instant when x=2 -
ok lor. i go scan.
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volume of water in cone = VOriginally posted by jay_rocks:diagram shows a vertical cross-section of a cointainer in the form of an inverted cone of height 60cm and base radius 20cm. the circular base is held horizontal and uppermost. water is poured into the container at a constant rate of 40cm³/s.
i) show tt, when depth of water in the container is x cm, the volume of water in the container is piex³/27 cm³
II)find rate of increase of x at the instant when x=2
radius = r
height = x
V = 1/3 pi r² x
(i) using similar traingles,
r / x = 20 cm / 60 cm
so r / x = 1/3
so r = 1/3 x = x /3
so V = 1/3 pi (x/3)² x
V = 1/3 pi x³/9
V = 1/27 pi x³
(ii) dV/dt = dx/dt * dV/dx
V = 1/27 pi x³
so dV/dx = 3/27 pi x²
so dV/dx = 1/9 pi x²
dV/dt = 40 cm³/s
when x = 2, dV/dx = 1/9 pi (2)²
so dV/dx = 4/9 pi
since dV/dt = dx/dt * dV/dx
so 40 = dx/dt * 4/9 pi
so dx/dt = (40)(9/4 pi)
so dx/dt = 90/pi cm/s -
go pong pong liow...bb
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hmm...
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nabeiz
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i tink i saw a purple hippo
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koon liows
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nitez folks
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hmm...
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morning
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morning
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morning
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morning monkOriginally posted by monkeybusiness:morning -
morning linyu
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morning $888Originally posted by LinYu:morning -
morning pctOriginally posted by poon cho tang:morning monk -
welcome to MY Rain concert in SingaporeOriginally posted by poon cho tang:morning $888