So i once heard someone say if you drop a penny and a bowling ball they will hit the ground at the same time. I didn't believe them, but then i heard it somewhere on the discovery channel and read it in some book, so i decided to do a bit of research and hoping someone can confirm. Newtons second law(from what i gathered) basically says that all objects fall with equaL acceleration regardless of mass. Or in other words they will each be effected equally by the downward force of gravity regardless of weight. right? However objects have a terminal velocity(the fastest rate of speed at which they can fall). In fluid dynamics an object is moving at its terminal velocity if its speed is constant due to the restraining force exerted by the fluid through which it is moving.(wiki) So basically here the 'fluid' through which an object would be moving is air. So doesn't this mean that unless you drop the objects from a high enough point to reach atleast one of the objects terminal velocity they will hit the ground at the same time?? i also found this- "The speed that things fall to the earth depends on two things, how fast they started falling and how long they have been falling. The equation for finding that speed, v, is: v = v0 + a*t where v0 is the initial speed something began falling, a is the acceleration or change in velocity is causing it to fall, and t is the time it has been falling. If the object is falling on the earth, the acceleration due to gravity is 9.8 m/s2. So, if you drop something off a very tall building by just letting it go, letting v0 = 0, then after 10 seconds, it will be moving at 98 m/s. The weight of the object only matters if there is air resistance." So if two objects have different weights but the same drag efficiency would they indeed hit the ground at the same time? and in what case would there be no air resistance? I still can't understand why i have heard that objects will hit the ground at the same time so much when its not 100% true. it depends on the height and drag efficiency of the objects. Right? Or should i stop eating mushrooms and trying to comprehend things?
if two objects have different weights but the same drag efficiency they do indeed hit the ground at the same time. a case where there is no air resistance is in that of a vacuum. in a vacuum with no gravity, one can nudge an object and it will continue at the same speed for ever.
HMMM.. But in the case of a falling object there would need to be gravity, that has to be the force which is making objects move towards another object because it will be constant, unlike a nudge which would undoubtedly apply a varying force. So yea if you drop to objects in a vacuum on earth they will indeed hit the ground at the same time regardless of mass because they will continue to accelerate at a constant rate until they hit the ground. So when people say if you drop a penny and a bowling ball from the same height the will hit the ground at the same time they need to add "in a vacuum"
https://www.youtube.com/watch?v=5C5_dOEyAfk ''So doesn't this mean that unless you drop the objects from a high enough point to reach atleast one of the objects terminal velocity they will hit the ground at the same time??'' If an object falls from a plane for example, the earth pulls it towards it(''going down'') at a constant acceleration, 9.8 m/s². This means that for every second that passes by, the object gains an additional 9.8 m/s of speed. However, the faster an object is going, the more air resistance it gains. Compare it like the object is standing still in mid-air, and the air is blowing at the object with an acceleration of 9.8 m/s², intuitively you would say that the object will gain more air resistance every second, right? Ok so, the object is falling with a continues acceleration, and also the air resistance is building up. At some point, the rate at which the air is exerting(giving) resistance to the object is the same as the rate of acceleration of the object. At this point the acceleration of the object is 0, which means the speed is constant. (So actually the object doesn't have a constant acceleration, it reduces with time because of the air resistance.) Also (as mentioned before) air resistance is independent of mass. It's dependent of the area of the object. Just like a parachute: When it's open, it has more area but the same mass as a closed parachute. Hence you fall slower with a open parachute then a closed one(doh ). Hope this helped.
Just a thought. Assuming terminal velocity is the same for each, air drag would be higher for the bowling ball assuming the coin is falling edge down. But the bowling ball having the higher weight, would it not reach terminal velocity faster and thus be further ahead of the coin or does the coin catch up because it is still accelerating while the ball has reached it maximum speed.
First off, the terminal velocity of a bowling ball and a coin are not the same. It depends on the area of the object and the mass. Second, the formule for terminal velocity is the square root of ((2*Mass*g(9.81))/(Density*Area*Drag coefficient)). So the higher the mass of an object is, the higher it's terminal velocity is. Consequently, a bowling ball hits the ground earlier then a coin.(Also, the larger the area is, the smaller the terminal velocity would be if you look at the formula). I'm not sure if it reaches terminal velocity faster, but it does gain a higher speed so the bowling ball will hit the ground first.
If Newtons laws were intended to be specific to only the Earth's variables, then he would have noted terminal velocity and air resistance. However, the tall building example is an interesting one (to a point) for this, because if you drop something with little mass, like a penny off of a tall enough building , then it would just fly back up because tall buildings have their own wind currents that surround them, since they're so tall.
https://www.youtube.com/watch?v=2Nyx8tPbWMI"]https://www.youtube.com/watch?v=2Nyx8tPbWMI They will reach the ground that the same time if dropped from the same height & time.
Thats because it's a small height, so the influence of the air resistance is so small that you can barely notice it.
Exactly Videos like that are the reason i made this thread, its simply not true... The mind fuck here is why there are people still claiming it to be true... Thanks for the input
