Question

A 5/8-in. (inside) diameter garden hose is used to fill a round swimming pool 4.6 m in diameter. Part A How long will it take to fill the pool to a depth of 1.6 m if water issues from the hose at a speed of 0.59 m/s ?

Answer 1

Answer:

t = 2.26 10⁵ s

Explanation:

Let's calculate the flow of water that comes out of the hose

         Q = A v

The area of ​​a circle is

        A = π r²

       Q = π r² v

Let's reduce the units to the SI system

       d = 5/8 in (2.54 10⁻² m / in) = 1.5875 10⁻² m

       r = d / 2 = 0.79375 10⁻² m

       Q = π (0.79375 10⁻²)² 0.59

       Q = 1.1678 10⁻⁴ m³ / s

Let's calculate the volume of the pool

       V = π R² h

       V = π (4.6 / 2)²  1.6

       V = 26.59 m³

Let's use a rule of proportions (rule of three), to find the time

       t = 26.59 (1 / 1.1678 10⁻⁴)

       t = 22.77 10⁴ s

       t = 2.26 10⁵ s

Answer 2

Answer:

Time taken to fill the pool(t) = 223529.41 s

Explanation:

The volume of water in the pool (V) = πd²h/4............... equation 1

Where d = radius of the pool, h = height of the pool

At a height of 1.6 m, the volume of water is

V(pool) = (3.143 × 4.6² × 1.6)/4 = 26.60 m³.

The volume of the hose is

V(hose) = πd²h/4........................... equation 2

And the rate of flow of water from the hose into the pool is

V(hose)/dt = (dh/dt) × (dV(hose)/dh)

Differentiating equation 2,

V(hose)/dt = πd²/4

where d = 5/8-in. =(5/8)×0.0254 =0.016 m, π = 3.143, dh/dt = 0.59 m/s

dV(hose)/dt = {(3.143×0.016²)/4} × 0.59

dV(hose)/dt = 0.000119 m³/s.

∴ time taken to fill the pool(t) = V(pool)/(dV(hose)/dt)

t = 26.60/0.000119

t = 223529.41 s.

Time taken to fill the pool(t) = 223529.41 s