TGIF! Some fun w/ Physics

Some fun w/ Physics as we head into the weekend...

Imagine you stood atop Mt. Everest and fired a cannon. Let's say that the Earth had no atmosphere. Can you fire the cannonball such that it goes in orbit around the earth? If so at what speed?

This was actually a thought experiment called Newton's Cannon, that Sir Issac Newton used to hypothesize that the force of gravity was universal, and it was the key force for planetary motion.

Will post more tomorrow, but let's see if anybody here has an answer or any further thoughts on this...


Here is the answer:

This is a concept called Newton's Cannonball. Here is from Wikipedia:

In this experiment Newton visualizes a cannon on top of a very high mountain. If there were no forces of gravitation or air resistance, then the cannonball should follow a straight line away from Earth, in the direction that it was fired. If a gravitational force acts on the cannon ball, it will follow a different path depending on its initial velocity. If the speed is low, it will simply fall back on Earth. (A and B) for example horizontal speed of 0 to 7000 m/s for Earth.

If the speed is the orbital speed at that altitude it will go on circling around the Earth along a fixed circular orbit just like the moon. (C) for example horizontal speed of at approximately 7300 m/s for Earth

If the speed is higher than the orbital velocity, but not high enough to leave Earth altogether (lower than the escape velocity) it will continue revolving around Earth along an elliptical orbit. (D) for example horizontal speed of 7300 to approximately 10000 m/s for Earth.

If the speed is very high, it will indeed leave Earth. (E) for example horizontal speed of approximately greater than 10 000 m/s for Earth.