"water is circulating in pipes in a two floor house. on the first floor the pressure is 340 kpa and the speed 2.8 m/s. the second floor is 4m higher. calculate the pressure on the second floor of the areas are A1 1m2 and A2 2m2"

Explanation:

We shall apply Bernoulli's equation of flow of liquid

1 / 2 ρ v² + ρ gh + P = constant

For calculating velocity in second floor

A₁ V₁ = A₂ V₂

1  x 2.8 = 2 x V₂

V₂ = 1.4 m /s

1 / 2 ρ v₁² + ρ gh₁ + P₁ = 1 / 2 ρ v₂² + ρ gh₂ + P₂

.5 x 10³ x 2.8² + 10³ x 9.8h₁ + 340 x 10³ = .5 x 10³ x 1.4² + 10³ x 9.8 x h₂ + P₂

P₂ = 3.92 x 10³ + 9.8  x 10³ ( h₁ - h₂ ) + 340 x 10³ - .98 x 10³  

= 3.92 x 10³ - 9.8  x 10³ x 4 + 340 x 10³ - .98 x 10³

= 303.74  x 10³ Pa

= 303.74 kPa .

there are no contact forces mentioned on the list of choices that you've provided.