To water the yard, you use a hose with a diameter of 3.0 cm. Water flows from the hose with a speed of 2.2 m/s. If you partially block the end of the hose so the effective diameter is now 0.50 cm, with what speed does water spray from the hose

v₂ = 79.69 m/s

Explanation:

The initial diameter of the hose, d₁ = 3.0 cm = 0.03 m

Initial Cross Sectional Area, A₁ = πd₁²/4

A₁ = (π* 0.03²)/4

A₁ = 0.00071 m²

The initial speed of water from the hose, v₁ = 2.2 m/s

The diameter of the hose after blocking the end, d₂ = 0.50 cm = 0.005 m

Cross Sectional Area of the hose after blocking the end, A₂ = πd₂²/4

A₂ = (π* 0.005²)/4

A₂ = 0.0000196 m²

To get the speed, v₂, at which the water spray from the hose after blocking the end, we will use the continuity equation:

A₁v₁ = A₂v₂

0.00071 * 2.2 = 0.0000196 v₂

0.001562 = 0.0000196 v₂

v₂ = 0.001562/0.0000196

v₂ = 79.69 m/s

answer: option c. i.e. electric current flowing “downhill” from the negative electrode to the positive electrode in a battery

explanation:

the water analogy to the circuits define the pipes (water flows) to the electric current. now, we know that the electric current flows from the positive terminal to the circuit (as shown in the diagram attached).

hence, option c is the correct answer.

see earlier