Which would hit the ground first ?

Question

Situation: There is no wind. On Earth, at an altitude of 50 m over sea-level.

1) You drop a dictionnary ( 1kg) and a kleenex box (0.5 kg) of the same volume.

2) You drop a basketball ( 5 L) and a steel ball ( 1L ) , which both have same mass.

3) You drop a basket-ball ( 1kg, 5L ) and a tennis ball ( 0.1 kg, 0.5 L)


Which will hit the ground first. Explanations would be appreciated

but isnt gravitational attraction GmM/r^2

So, the heavier the object , the bigger the attraction.

Answer 1

Hello polo -

The greater the mass, the greater the attraction - true, but that greater attraction is just enough to pull that greater mass at the exact same acceleration as the smaller mass with a smaller attraction. Neglecting the effects of air resistance (which is absolutely proper in this case), all of the objects will hit the ground after the exact same amount of time from release. In fact, Galileo demonstrated this hundreds of years ago by dropping different objects from the top of the Leaning Tower and demonstrating that they did indeed hit simultaneously, regardless of their individual masses.

The real nature of gravity is better understood not as a force, but as an acceleration that is applied to all objects within the gravitational field of a massive object. The force is just a back-calculation based on a convenient formula, the size of the masses involved, and a fudge factor (G) that Newton derived to make the force come out right. It works to get the right answer, but even Newton knew that it does nothing to advance the understanding of how gravity works. Einstein understood it better, but that was a hundred years ago and we still have a ways to go.

ADDED: Of course, if the basketball were a lot bigger, then its gravitational field would accelerate the earth up toward it a little faster than the tennis ball would, resulting in the earth contacting the basketball a fraction of a second sooner - this effect is really negligible, but may be causing some confusion).

Answer 2

1) Dictionary
2)Steel Ball
3)tennis ball

Answer 3

they all hit the ground at the same time, no matter their weight. its true, as long as theres no wind resistance. they all simple fall at a rate of 9.8m/s. you can try it yourself, get a pingpong ball or other small round thing and a baseball and they hit the ground a the same time...

Answer 4

Gravity is what controls the falling to the Earth. So, in that regard, they would all hit at the same time, because they all have the same amount of gravity on them.

Answer 5

1. same time
2. same time
3. same time

All items hit the ground at the same time regardless of the mass. Except if there is air resistance. They all fall at
2
*** 9.8m/s [(9.8 meters per second squared) 9.8 meters per second per second] I hope I helped! :)

Answer 6

there can be wind resistance ( due to air) even if there is no wind. that effects time to fall based on the shape of the object.



but if you mean what i think you mean , they all hit the same.

Answer 7

in each case the one with the least air resistance would hit the ground first it doesn't depend on mass

Answer 8

a) Dictionary
b) Basketball
c) Basketball

jeez- I hope that's right

Answer 9

they will all hit at the same time, gravity pulls on each equally