A non -viscous incompressible fluid is pumped steadily into the narrow end of a long tapered pipe and emerges from the wide end . The pressure at the input is greater than at the output . A possible explanation is :

 v₂ =

Explanation:

This phenomenon is explained by the continuity equation in fluids

           v₁A₁ = v₂A₂

where the subscript 1 is for the input narrow part and the subscript 2 for the wide part

         v₂ =

consider the cross section at each point

           A₁ = π r₁²

           A₂ = π r₂²

we substitute

          v₂ =

therefore the exit velocity is less than the entrance velocity of the fluid.

We can also analyze the situation using Bernoulli's equation

         P₁ + ρ g v₁² + ρ g y₁ = P₂ + ρ g v₂² + ρ g y²

       if we assume a horizontal system y₁ = y₂

         P₁-P₂ = ρ g (v₂² - v₁²)

the assestment will probley apele with cause and effect

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