A block and tackle or only tackle is a system of two or more pulleys with a rope or cable threaded between them, usually used to lift heavy loads.
Answer:
Increase in speed.
Explanation: Since mass must be conserved, if the cross section of the flow tube is not the same, that is varies, the flow speed must change to conserve mass.
This means that there is a non-zero net force acting on the fluid that causes the fluid to increase or decrease in speed depending on whether the fluid is flowing through a portion of the tube with a smaller or larger cross
Arteries push blood to the rest of the body after leaving the heart.
The sources of the waves must be coherent, which means they emit identical waves with a constant phase difference and the waves should be monochromatic - they should be of a single wavelength.
~Sanjith U.