When is an object free fall?

Answer 1

Start your presentation by defining what you are talking about: free fall.

Free fall...when an object moves through the spatial dimensions under force of gravity and no other forces with one possible exception, air resistance.

So this exempts a glider, for example, because it has wings and lift forces. And it exempts anything, like a rocket, that is self-propelled. That's another force other than gravity and air resistance. But a person descending without a parachute is in free fall because gravity is pulling him downward while air resistance is pulling upward. Or a Baseball in a trajectory is in free fall because while in flight, and if we discount the minimum air resistance, only gravity acts on the ball as in comes back to Earth after passing over the fence for a home-run.

Notice that free FALL does not necessarily mean the object is falling all the time. In the baseball case, the ball clearly rises for a bit before it starts back down. Nevertheless, it is in free fall the whole trajectory as it's acted on only by gravity (discounting air resistance).

Then show day to day cases where free falling objects are found. For example, when playing ball (any of them), those balls while in the air are in free fall. You might go high tech and point out that satellites go into free fall when they re-renter the Earth's atmosphere and burn out. Not the shuttle, though, it develops lift. You might also point out that when the free falling parachutists pops his chute, he is no longer in free fall as most if not all chutes also develop lift and the chutist uses that lift to guide himself to a safe landing spot.

Answer 2

An object is in free fall whenever it is falling directly towards the earth. If you drop ( not throw) a rock straight down off of a cliff, it will be in free fall, falling at 9.8 m/s2. It does not have a horizontal component for velocity.

Now if you throw a rock straight up, its acceleration going up will be -9.8 m/s2 because gravity pulls downward, and the velocity of your object going up is positive. Since the object will be slowing down as it reaches its highest point, velocity and acceleration will have opposite signs.

On the way down, the object is now in free fall.

Answer 3

An object is in "free fall" when the only force on it is the force of gravity.

Answer 4

depends on how long it has been falling and what kind of resistance (such as air) it encounters; also depends upon the gravitational pull it is receiving.

Answer 5

An object is said to be in freefall when gravity is the only force acting upon it. Gravity is defined as the force that pulls objects toward the earth.

Answer 6

An object is in free fall when no forces act on it in the y-direction except gravity

(apex) the only force acting on it is earth's gravity.

Answer 7

It is considered as 'free fall' when the only force

acting on the object is the force of gravity.