Gravity and Motion?

Question

How does air resistance affect the acceleration of falling objects?

Why an astronaut in an orbiting spaceship floats?

Hows is an orbit formed?

When the falling object stops ----?----, it has reached ----?---- velocity.

Answer 1

air resistance put an aptrust to the falling body

astr... floats cuz of zero gravity

due to centripetal accelaration

blank 1 = accelarating

blank2 = critical

Answer 2

If you dropped a feather and an anvil on the moon they would fall at the same rate of acceleration and hit the dirt at the same time. This is because there's no atmosphere on the moon. Here on earth the feather would flutter because of air resistance. Air resistance has less effect on the anvil because it is more massive. As a result the anvil falls faster.

An astronaut in orbit floats for the same reason that a skydiver floats when he or she is in free-fall. The jumper in free-fall is accelerating toward the center of the earth and feels weightless (ignoring air resistance). An orbiting object is also accelerating toward the center of the earth but it also has circular motion around that center due to the pull of gravity. It's like walking in circles around a point, you're constantly changing your course in the direction of that point but your never get there. A stable orbit is an eternal free-fall.

When the falling object stops "accelerating", it has reached "terminal velocity". When the skydiver jumps he/she accelerates until the air resistance is strong enough to stop the acceleration and then the jumper falls at a constant speed - that's the terminal velocity. When the shoot opens the air resistance is much greater and the terminal velocity becomes slow enough that jumper lives to jump another day. Don't try skydiving on the moon because there's no air resistance, thus no terminal velocity. You'd just keep accelerating until you dug a new crater.

Answer 3

Air resistance causes a drag force in the direction opposite to the direction of fall. When the two are equal, terminal velocity is achieved. This is usually achieved in cases of spherical objects. A good real life example is a cat. If it falls from a high building, it curls up into ball shape, attains terminal velocity and then opens before landing, which acts like a parachute. Hence it lands without getting hurt.

Astronaut floats due to zero gravity, or put another way the gravitational pull gets cancelled out by the centrifual force.

Answer 4

Air resistance provides a force proportional to the area of the object times its velocity squared. Eventually, this can balance the gravitational acceleration.

The net force on the astronaut in an orbiting spaceship is the gravitational attraction of the astronaut to the ship, which is very, very small.

An orbit is formed when an object is traveling fast enough to avoid falling to the surface of the attracting body, and slow enough for the attracting body to keep it from flying off into deep space.

accelerating, terminal

Answer 5

Air resistance is just friction related to relative velocity... If its equal to the force of gravity your terminal velocity has been achieved.

Acceleration is almost constant, you "float" because you fall at the same rate as everything around you...

If you fall constantly in a circle you are in orbit.

Answer 6

carnac has the magnificent answer