Answer:
it is a catecholamine that stimulates alpha1 adrenergic receptors and, slightly, beta1 adrenergic receptors, without beta2 effect. It is the vasoconstrictor drug par excellence.
Making rough estimate of physical quantities is useful because it allow us to have an idea of how big or small a quantity is, it gives us the near result of the real quantity a matter contains. The approximate quantity obtained will give us information about the size of the quantity.
Yes this is true sort of like when light rays pass through water particles in the atmosphere and create a rainbow :)
