which would fall faster?

Question

if a copper plate and a steel plate of the same size and shape were released from the same height.

Answer 1

In a vaccum - both the same.

Using Newton's Law of Gravitation, the acceleration of each plate is independant of its mass and thus they would fall at the same rate.

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In air - The Copper plate falls faster.

Everyone knows the acceleration due to gravity is the same and that the drag force is the same (given the same cross-sectional area). But these cannot be combined together. If two objects with different masses have an equal (drag) force applied, the (de)accelerations are different.

F(net) = F(gravity) - F(drag)
F(net) = GMm/d^2 - F(d)
a(net) = GM/d^2 - F(d)/m

Thus acceleration depends on mass - because the drag force doesn't.

Therefore the drag will slow the steel plate more - and the copper plate will hit the ground first.

Obviously, the difference is fairly insignificant in real world time, but the point remains valid.

Answer 2

I don't know the exact compounds of copper or steel but the laws of physics will tell you if you know them.
Gravity excelerates all things on earth in a downward direction at a set speed. Air resistance, mass, and time (how long it is in the air) all effect how fast something goes.

So, if a steel plate and copper plate as you described, were dropped from,say 10 feet, they would hit close to the same time. But my guess is that steel would fall slightly faster cause it is "heavier" (meaning that it has more mass, and therefor, more for gravity to pull on) But if the height is increased to say, 100000 feet, Air resistance plays a bigger role. "terminal velocity" is when the acceleration of gravity can no longer overcome the force of air resistance and that is as fast as a given object will fall. However, in a vacum enviroment, Air restistance would no longer effect speed in which falls faster. Since I have never had the oppretunity to test these ( and I am not sure If I remember these right, I had to leave school right as the test was coming up) I wouldn't trust me entirely on this.
But I think steel would hit first, if only marginally first.

Answer 3

the same with or without air resistance. If they have the same shape then they have the same surface area. Drag and terminal velocity is a function of surface area, not mass or density. Any two objects with the same shape will fall at the same rate in any fluid [i.e. air] as long as gravity is constant.

Answer 4

neglect viscosity.............(even if we consider it, as both steel and copper are massive than paper or husk, it doesn't make difference.)

t= sqrt((2*h)/g)
The equation doesn't has mass in it. That means mass doesn't effect acceleration, velocity or time of fall.
s= u*t + 0.5*g*t^2
v=u+gt
still no place of mass in the equation

Note: 'g' varies with height, latitude but not with mass of object

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WHAT ARE YOU THINKING, IS IT VARYING MAGNETIC FLUX THROUGH THEIR BODIES WHILE FALLING ON SURFACE OF EARTH BY LENZ's LAW WILL Generate electric field and start deceleration. If thats the case then net effect of gravitation plus lenz's law should be considered

Answer 5

Same time. Similar experiment was carried out by Galileo from the leaning tower of Pisa( He had used objects of different sizes. Even they reached earth at the same time)

Answer 6

In a vacuum they would fall at the same rate. Dropped from lets say an air plane it would depend on their terminal velocity.

Answer 7

They fall with the same acceleration.

Cheers!

Answer 8

Copper, as it is more dense than steel. Therefore, being the same size and shape, copper would be denser and therefore heavier, falling faster

Answer 9

They will fall AT THE SAME TIME if we neglect air resistance!

Answer 10

on earth: steel.
in a vacum: neither, they would fall at the same rate