Question 170: Properties of Matter

Question

Water from a tap emerges vertically downwards with an initial speed of 1.0 ms
–1
. The cross-sectional area of
the tap is 10
–4
m
2
. Assume that the pressure is constant throughout the stream of water and that the flow is streamlined. The cross-sectional area of the stream, 0.15 m below the tap would be : (Take g = 10 ms
–2
)

Accepted Answer

Using BernoullieÃ¢ÂÂs equation $${v_2} = \sqrt {v_1^2 + 2gh} $$
Equation of continuity
A
1
V
1
= A
2
V
2
(1 cm
3
)(1m/s) = $$\left( {{A_2}} ight)\left( {\sqrt {{{\left( 1 ight)}^2} + 2 	imes 10 	imes {{15} \over {100}}} } ight)$$
$$ \Rightarrow {A_2}\left( {\ln c{m^2}} ight) = {1 \over 2}$$
$$ \Rightarrow {A_2} = 5 	imes {10^{ - 5}}{m^2}$$

Answer

5 × 10
–4
m
2

Answer

2 × 10
–5
m
2

Answer

5 × 10
–5
m
2

Answer

1 × 10
–5
m
2

Properties of Matter

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