To solve the problem it is necessary to apply the equations related to the Poiseuilles laminar flow law, with which the stationary laminar flow ΦV of an incompressible and uniformly viscous liquid (also called Newtonian fluid) can be determined through a cylindrical tube of constant circular section. Mathematically this can be expressed:
Where:
are the viscosities of the concrete before and after the increase
l = Length of the vessel
= Radio of the vessel before and after the increase
= Change in the pressure
The rates of flow before and after he increase
Our values are given as:
10 times her resting rate
95% of its normal value
Increase of 50%
Plugging known information to get
Therefore the factor of average radio of her blood vessels increased is 1.589 the initial factor after the increase.
The speed of sound is greater in ice (4000 m/s), then in water (1500 m/s), then in air (340 m/s). The explanation for this is the differente state of the matter in the three cases.
In fact, sound waves travel faster in solids (like ice), then in liquids (like water), then in gases (like air). This is because the speed of the sound wave depends on the density of the medium: the greater the density, the faster the sound wave. This can be easily understood by thinking at how a sound wave propagates: a sound wave is a vibration of molecules, which is transmitted throughout the medium by collision of the molecules. Therefore, the smaller the spacing between the molecules (such as in solids), the more efficient is the propagation, and so the sound wave is faster. On the contrary, there is a large spacing between molecules in gases (such as in the air), so there are less collisions between the molecules and so the wave is not transmitted efficiently, and so it has less velocity.
Theoretically, if the objects have the same mass and are moving towards each other at a speed of
, after a perfectly elastic collision, the object A is supposed to move with the same velocity in the opposite direction.
