Answer:
12 m/s
Explanation:
Using the continuity equation, which is an extension of the conservation of mass law
ρ₁A₁v₁ = ρ₂A₂v₂
where 1 and 2 indicate the conditions at two different points of flow, in this case, point 1 is any normal position in the pip and point 2 is the conditions at the restriction.
ρ = density of the fluid flowing; note that the density of the fluid flowing (water) is constant all through the fluid's flow
A₁ = Cross sectional Area of the pipe at point 1 = (πD₁²/4)
A₂ = Cross sectional Area of the pipe at the restriction = (πD₂²/4)
v₁ = velocity of the fluid flowing at point 1 = 3 m/s
v₂ = velocity of the fluid flowing at The restriction = ?
ρ₁A₁v₁ = ρ₂A₂v₂
Becomes
A₁v₁ = A₂v₂ (since ρ₁ = ρ₂)
(πD₁²/4) × 3 = (πD₂²/4) × v₂
3D₁² = D₂² × v₂
But
D₂ = (D₁/2)
And D₂² = (D₁²/4)
3D₁² = D₂² × v₂
3D₁² = (D₁²/4) × v₂
(D₁²/4) × v₂ = 3D₁²
v₂ = 4×3 = 12 m/s
Answer:
There is absolutely No relationship between the weight of an object (which is constant) and the frictional force. If a block is sliding on a surface, that surface will be exerting a force on the block. That force can be resolved into a component parallel to the surface (which we call the frictional component), and a component perpendicular to the surface (called the normal component). For many situations, we find experimentally that the frictional component is approximately proportional to the normal component. The frictional component divided by the normal component is defined to be a quantity called the coefficient of kinetic or sliding friction. The coefficient of kinetic friction obviously depends on the nature of the surfaces involved. The normal component on an object can be decreased if you pull in the direction of the normal component (the weight does not change). However pulling this way on the object not only decreases the normal component, but it also decreases the frictional component since they are proportional. This is why it is easier to slide something if you pull up on it while you push it. If you push down, the normal and frictional components increase so it is harder to slide the object. The weight of an object is the downward force exerted by Earth’s gravity on that object, and it does not change no matter how you push or pull on the object.
7000w + 1637kw =8637kw+25.0m=loud sound