Explanation:
A) Gauge pressure is:
P = ρgh
P = (1000 kg/m³) (9.8 m/s²) (3 m)
P = 29,400 Pa
B) Using Bernoulli equation:
P₁ + ½ ρ v₁² + ρgh₁ = P₂ + ½ ρ v₂² + ρgh₂
ρgh₁ = ½ ρ v₂²
gh₁ = ½ v₂²
v₂ = √(2gh₁)
v₂ = √(2 × 9.8 m/s² × 3 m)
v₂ = 7.67 m/s
Notice you get the same equation using conservation of energy.
KE = PE
½ mv² = mgh
v = √(2gh)