It is known that objects of different mass will fall at the same speed bit of you drop a feather and coconut the coconut will fall faster.Why?

3 Answers
May 30, 2018

Here you need to consider the resistence of air!

Explanation:

The object in absence of air would fall exactly at the same rate and reach the ground at the same time. The air makes it difficult because opposes a resistance that in the case of the feather will interfere with its motion.

To see this try the following experiment.
Take a book and a foil of paper:
First drop the two side by side. You'll see that the book seems to fall faster (and indeed should reach the ground first).
enter image source here
Now place the paper on top of the book and drop both of them. The effect of the air on the paper will be "cancelled" by the bulk of the book so that now they will reach both the ground at the same time!
enter image source here

May 30, 2018

#"Because of air resistance."#

Explanation:

#"The feather has a bigger surface per unit weight."#
#"Like this the feather has bigger air resistance."#
#"Most formulas in falling under gravity are neglecting the air"#
#"resistance."#

#"Without air resistance :"#
#F = m * a = m * {dv}/dt = - m * g#
#=> a = - g#
#=> {dv}/dt = -g#
#=> v = v_0 - g* t#
#=> dx/dt = v_0 - g*t#
#=> x = x_0 + v_0 * t - g*t^2/2#

#"With air resistance :"#
#F = m * a = m * {dv}/dt = c * v^2 - m*g#
#"(c is a constant depending on the Cx of the object among others)"#
#"A coconut has a lower Cx than the shape of a feather."#
#"The Cx is named the drag coefficient."#

May 30, 2018

See answer below

Explanation:

Two objects that only have the force of gravity acting on them, will fall with the same acceleration #g = 9.8 m/s^2; " "g = 32.2 (ft)/s^2# and will therefore hit the ground at the same time.

When you drop a feather, air resistance acts on all the surfaces of the feather. This causes the feather to slow down.

Air resistance depends on two factors: the speed of the object (increased for example by throwing it), and its surface area.