45.
(a) The equation of continuity leads to
v
2
A
2
= v
1
A
1
=
⇒ v
2
= v
1
r
2
1
r
2
2
which gives v
2
= 3.9 m/s.
(b) With h = 7.6 m and p
1
= 1.7
× 10
5
Pa, Bernoulli’s equation reduces to
p
2
= p
1
− ρgh +
1
2
ρ
v
2
1
− v
2
2
= 8.8
× 10
4
Pa .