The conventional signal used by sailboats in conditions of reduced visibility such as heavy fog is one long blast followed by two short blasts.
The blasts help other boat operators locate one another's vessel in a condition where it is not easy to see. This signal is repeated in order to not only let others know of the vessel's position, but also help them know which way it is traveling. For example, if the blasts start to become distant, then the sailboat is travelling away from you.
Answer:
Explanation:
Time of flight = 2 x u sinα / g where u sinα is vertical component of projectile's velocity u .
So Time of flight = 2 x vertical component / g
vertical component = constant
g is also constant so
Time of flight will also be constant .
It will remain unchanged .
Answer:
Ptolemy proposed a model, he reference system is centered on the Earth
Copernicus, proposed a deferent system, this system is centered on the Sun, where it is at the origin of the system
Explanation:
Thousands of years ago, Ptolemy proposed a model to explain the movement of the planets and stars in the sky, in this model the reference system is centered on the Earth, so each body is orbiting in different spheres around the Earth as its center, this system had very complicated calculations and curves to be able to explain the orbits of the planets.
More recently Copernicus, proposed a deferent system, this system is centered on the Sun, where it is at the origin of the system, in this system the movement of the planets are ellipses, which is a much simpler explanation and has been widely accepted, in current systems the reference system is fixed in the bodies more massive, since this simplifies the explanation of the movements.
Periods<span> going left to right. The periodic table also has a special name </span>for<span> its vertical columns. Each column </span>is<span> called a </span>group. The elements in eachgroup<span> have the same number </span>of<span> electrons </span>in the<span> outer orbital.</span>
