Question

100 POINTS.
Please provide explanation.

Thank you

Answer 1

Step-by-step explanation:

Regarding the point of "Flow rate is proportional to the pressure difference and the radius raised to the fourth power", flow rate depends on pressure, cross-section area and speed. As speed also depends on cross-section area, flow rate becomes dependent on pressure and cross-section area squared.

In a round pipe like blood vessel, the cross-section area is equal to pi*radius squared. So flow rate is proportional to the pressure difference and (radius squared) squared; i.e. the radius raised to the fourth power.

The new flow rate = (1.12)*(0.84)^4

=0.5576 or 55.76% of the original flow rate

Answer 2

(a) 0.829 m/s

(b) 3.27 m/s

(c) 0.000153 m²

55.8%

Step-by-step explanation:

(a) Flow rate equals velocity times cross-sectional area. (1 L = 0.001 m³)

Q = vA

(0.001 m³ / 2.00 s) = v (48 × π (0.002 m)²)

v = 0.829 m/s

(b) Use Bernoulli equation. Choose point 1 to be the exit of the pump, and point 2 to be exit of the shower head. Choose 0 elevation to be at point 1.

P₁ + ½ ρ v₁² + ρgh₁ = P₂ + ½ ρ v₂² + ρgh₂

(1.50 atm × 1.0×10⁵ Pa/atm) + ½ (1000 kg/m³) v² + 0 = (1 atm × 1.0×10⁵ Pa/atm) + ½ (1000 kg/m³) (0.829 m/s)² + (1000 kg/m³) (10 m/s²) (5.50 m)

1.50×10⁵ Pa + (500 kg/m³) v² = 1×10⁵ Pa + 414.5 Pa + 55000 Pa

v = 3.27 m/s

(c) Flow rate is constant.

Q = vA

(0.001 m³ / 2.00 s) = (3.27 m/s) A

A = 0.000153 m²

Flow rate is proportional to the pressure difference and the radius raised to the fourth power.

Q ∝ ΔP r⁴

Q₂/Q₁ = (ΔP₂/ΔP₁) (r₂/r₁)⁴

Q₂/Q₁ = (1.120) (0.840)⁴

Q₂/Q₁ = 0.558

The flow decreases to 55.8% of the original value.