Chlorpheniramine is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose. Chlorpheniramine is used to treat runny nose, sneezing, itching, and watery eyes caused by allergies, the common cold, or the flu.
The mean orbital velocity of Earth is about 29.783 kilometers per second. That's the speed the planet is moving through space in its orbit about the sun. Earth's speed varies a bit because its orbit is slightly eccentric, but that's why we say mean orbital velocity. One can calculate this value by knowing two facts:
Earth's mean orbital speed is the average speed at which the Earth revolves around the sun. This is defined in two different ways, based on the sidereal year and the tropical year. The sidereal year is the time it takes for the Earth to revolve once around the sun with respect to the distant stars.