If a cannonball is fired from a tall mountain, gravity changes its speed all along its trajectory.?

Question

If a cannonball is fired from a tall mountain, gravity changes its speed all along its trajectory. But if it is fired fast enough to go into circular orbit, gravity does not change its speed at all. Why?

Answer 1

Gravity changes a projectile's speed whenever there's a component of motion that is parallel to the direction of gravity.

To put it in simpler terms, when a projectile moves closer to the earth, it speeds up; when it moves farther from the earth, it slows down. If it's moving perpendicular to the force of gravity, it neither speeds up nor slows down.

When a cannonball is fired relatively slowly, gravity causes its path to curve more sharply than the curvature of the earth. This makes it move closer to the earth, so it speeds up.

But if you fire the cannonball fast enough, the projectile's curvature exactly matches the earth's curvature. It doesn't move any closer to the earth, so it doesn't speed up or slow down.

Answer 2

There are many factors to analyze.
Imagine a really tall mountain where gravity is less than here at see level (9.8 m/s^2). When the ball is fired say horizontally, it will decelerate due to air friction but that's another parameter to factor in. It will drop vertically. If we forget the horizontal component, firing horizontally is just the same as letting the ball drop from the high mountain. It would fall on the mountain, so let us drop the ball from a plane flighing high. The gravity will change and hence the speed will increase non-linearily (increase and increase more).
Orbiting... The change in direction is also an acceleration as you may know. When a satellite is going around the earth, earth is pulling on the satellite by gravity but the satellite is going so fast that it stays in orbit, it is being pulled away by the radial component of it's speed. Gravity accelerate the satellite toward the earth. There is a balance in between the radial componenent and the gravity at the satellite's "height". This balance keep the satellite in orbit.

Answer 3

because it does, its law of physics.
the air ---->>> <<---(cannonbal)


gravitiygravitiygravitiygravitiygravitiy

the air will confront the cannonball, the gravity will pull it down.
for example the world isn't round just because god made it like that. the gravity made it round. it pulls everything to the core with a certain power.

the world is an inviroment, your circular orbit thing only takes place in space, where there is no inviroment. the cannonbal will go endless into the vaccuum of space with the same speed as you have fired it with.

there is no air to slow it down or gravitity to pull it

atleast untill it reaches another gravity point and it will be drawn to it.

Answer 4

False.

The international space shuttle is in orbit and it is falling. If it didn't boose it would fall in several months. The moon's orbit is currently stable, but someday that too will change.

It will not stay at it's speed as gravity will slow it down.

Gravity even gets the better of the speed of light, so you probably won't ever find a cannon that could accomplish that.

Answer 5

true
cintrifical force oposes geavitaional fordce and the "cannonball" would not be affected by gravity