Time for Free Fall from Great Distances

In summary, the equations of a falling object dropped from a 1000 foot tall building are simple: s=1/2(at^2), v(final)=(2as)^.5, and v(final)=at, where a is the acceleration due to gravity and s is the height of the building. However, these equations cannot be used for objects dropped from 5000 miles in space, as the initial acceleration is smaller and gradually increases to the value of a at the surface of the earth. There are simple formulas for relating distance fallen, final velocity, and time without using integrals or differential equations, such as conservation of energy for calculating velocity at a given distance. However, determining the time without using calculus is not possible.
  • #1
Thecla
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The equations of a falling object dropped from a 1000 foot tall building are simple:

eq 1 ##s=1/2( at^2)##

eq 2 ##v(final)=(2as)^.5##

eq 3 ##v(final)=at##

where a is the acceleration due to gravity at the surface of the earth
s is the height of the building, t is the time it takes to fall

If we dropped an object from 5000 miles in space we can't use these formulae because the acceleration initially is smaller, gradually increasing to the value ,a, at the surface of the earth.

Are there simple formula that relate the distance fallen to time,eq 1; the final velocity to distance eq 2 and the final velocity to time eq3 that do not involve integrals or differential equations, just simple algebra
 
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  • #2
You could get velocity at a given distance by using the conservation of energy. No calculus, just algebra. But I don’t know how to get the time without it.
 
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1. How does distance affect the time for free fall?

The greater the distance, the longer the time for free fall. This is because the force of gravity increases with distance, causing objects to accelerate faster as they fall.

2. What is the formula for calculating free fall time?

The formula for calculating free fall time is t = √(2h/g), where t is time, h is distance, and g is the acceleration due to gravity (9.8 m/s²).

3. Does the mass of the object affect the free fall time?

No, the mass of the object does not affect the free fall time. All objects, regardless of their mass, will fall at the same rate due to the acceleration of gravity.

4. How does air resistance affect the time for free fall?

Air resistance can affect the time for free fall by slowing down the object's acceleration. This is because air resistance creates a force in the opposite direction of the object's motion, causing it to fall slower.

5. Can the time for free fall be longer than the calculated formula?

Yes, the calculated formula for free fall assumes that there is no air resistance and the object is falling in a vacuum. In reality, air resistance can slow down the object's acceleration, making the time for free fall longer than the calculated formula.

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