To change from mass to weight is Fw = 30 kg * 9.8 m/s^2 = 294 N. To change from weight to mass divide by gravity (9.8 m/s^2).
It means that velocity not only has a size, but it also has a direction.
Some other vector quantities are force and acceleration.
They have sizes and directions.
Temperature, cost, and weight are quantities with only size and no direction.
Those are called "scalar" quantities.
The approximate height of the tsunami in Alaska in 1958 is 1720ft
Planets orbit the sun in the paths which are known as elliptical orbit. Each planet has its own orbit around the sun and direction in which all the planets orbit around the sun are the same. These orbits were well explained by the astronomer Kepler. The gravity of the Sun keeps the planets in their orbits. They stay in their orbits because there is no other force in the Solar System which can stop them.
