0

Still, I don't understand how come the satellites won't fall into earth. I know the general explanation to this question is that the satellite's horizontal velocity is too fast that makes the gravity impossible to pull it to the earth.

This, for me, sounds like the gravitational force need to take a few moments to sense the existence of this object and then pull it downward, just right at the moment the earth notice the object and begin to pull it for its position, it had already moved to another place.

Well, I think since the vertical velocity id independent of horizontal velocity, therefore, no matter how fast the horizontal speed is, it will not prevent the gravity to pull it straight down to the earth, isn't it?

can someone point out what's wrong with my understanding here?

Qmechanic
  • 201,751
Sherri
  • 37
  • 1
    I am confused about your distinction between "horizontal" and "vertical" since the orbit is elliptical / circular. Also, think about an object you spin on a rope. Why doesn't the object hit your hand? – BioPhysicist May 21 '20 at 19:32
  • by that, I mean the two components of an object moving in the direction with a angle – Sherri May 21 '20 at 19:47
  • I know the answer to your question, it is because the object's inertia, which is property of mass that resist to change. However, I couldn't really able to understand this concept – Sherri May 21 '20 at 19:49
  • What coordinate system are you using when you say "horizontal" and "vertical?" – Sandejo May 21 '20 at 19:50
  • horizontal means on the x-axis. vertical means on the y-axis – Sherri May 21 '20 at 19:51
  • Possible duplicates: https://physics.stackexchange.com/q/9049/2451 and links therein. – Qmechanic May 21 '20 at 19:53

2 Answers2

0

Well, I think since the vertical velocity is independent of horizontal velocity, therefore, no matter how fast the horizontal speed is, it will not prevent the gravity to pull it straight down to the earth, isn't it?

Without actually doing the math,the gravity is indeed pulling it,thus the motion is downwards as well as side wards.Its just that it has a velocity in horizonatal direction also so it follows a different path to fall down, now if the velocity is good enough the path may be a closed one like an ellipse or circle! So I say you still can say it’s falling down but it’s velocity is delaying the fall and thus as the function of velocity we get different paths(open or closed).And the satellites’ velocity is such that it has a closed path. path

P-S-S
  • 127
0

"Well, I think since the vertical velocity id independent of horizontal velocity, therefore, no matter how fast the horizontal speed is, it will not prevent the gravity to pull it straight down to the earth"

Here's one way of looking at it... If you throw a ball horizontally, it doesn't immediately drop to the ground, does it? It travels horizontally for a distance, while falling at the same time. But if you could throw the ball hard enough it would never reach the ground because the ground would be dropping away, due to the Earth being a sphere!

Philip Wood
  • 35,641