According to the Bernoulli's equation,the pressure difference between the wide and narrow ends of the pipe is given by

Here,
is the velocity of water through wide ends of cylindrical pipe and
is the velocity of water through narrow ends of cylindrical pipe.
Given, 
Now from equation continuity,
.
Here,
and
are cross- sectional areas of wide and narrow ends of cylindrical pipe.
As pipe is circular, so
.
At the second point, the diameter is halved, which means the radius is also halved. Therefore,


Substituting these values with the density of water is
in pressure difference formula we get.

Answer: A and C (i took the test)
Explanation: Hope this helps:)
Answer:
(a) 70cm³
(b) 805 grams
Explanation:
(a) V = L×B×H
= 7cm×5cm×2cm
= 35cm×2cm
= 70cm³
(b) Mass = Volume × Density
= 70cm³ × 11.5g/cm³
= 805 grams