Pluto was discovered by the astronomer Clyde Tombaugh in February 1930. It was given the status of the ninth planet of the solar system.
As telescopes, particularly in on satellites, improved, more objects were discovered which caused a problem that they were quite small and some astronomers didn't think they qualified as being planets.
The International Astronomical Union (IAU) had a vote which was very close. They defined three criteria which a planet must satisfy.
It must be large enough for gravity to overcome structures of materials and make it spherical. Most bodies are flattened spheroids due to rotation.
It must orbit the Sun.
It must have cleared its orbit of other bodies other than moons.
The IAU created a new definition of an object called a dwarf planet which only satisfies the first two criteria. Pluto fails the third criterion, so it was demoted to a dwarf planet.
Many people, including myself, still consider Pluto to be the ninth planet.
To be pedantic, Jupiter has a lot of asteroids in its orbit at its two Lagrange points. They are called trojan asteroids. So, this means that Jupiter fails the IAU's third criterion and should be a dwarf planet, which it is certainly not!
Average speed=total distance travelled/time
Answer:
Option (C)
Explanation:
Flash flood refers to the sudden flood that occurs in a particular area due to the heavy and excessive amount of rainfall, often accompanied by thunderstorms within a few hours. It releases a huge amount of water due to the failure of natural levee as well dam. They are very devastating. During flash flood, the water exerts a massive force which can make vehicles float over water. The <u>six inches of water</u> that flows over an area has the capacity to lift the tyres of small vehicles and carry hem further away.
Thus, the correct answer is option (C).
Answer:
25kJ
Explanation:
K = 1/2 mv^2 = 1/2 x 2000kg x (5.0m/s)^2
= 25 x 10^3 J = 25kJ