Question

will the heavy object fall faster than the lighter one in presence of air if they are of same material amd shape?

Answer 1

Dear student,
Really good question. But there's a slight misunderstanding. If they are of same material (hence density will be same) and shape(which I assume that they have same shape or volume), how one will be heavier than other? After all they've the same mass, right? Anyway, I get what you've asked for. We know both heavy and light objects fall with same speed under gravity(gravity only) as they are under same acceleration, g. You can use Newton's laws to find the time for fall, speed or anything. They will fall together. Now coming to some real life applications and encounters, there is air resistance. We can see air resistance as a kind of viscous drag or fluid resistance( of course air is a fluid). This mainly depends on the material of falling body, it's shape, surface area in contact with the fluid, etc. So, if a heavier and a lighter object falls, both of same shape, we CANNOT say the lighter one will fall faster, unless the we have a the above data. We need to know how much drag will the object or the material will feel, as this will determine the acceleration (which is
g -retardation of air). This inturn will determine how long it will take to fall, it's speed and so on. I feel you got the point. You will come across all these in your upcoming chapters and classes.
Thank you.