Question #889b0

2 Answers
Mar 29, 2015

Freefall describes any situation where the only force acting on an object is gravity.

This force is the object's weight. You would see free fall in the absence of air resistance. Google YouTube Brian Cox gravity

Free fall is when an object is only subject to the force due to gravity, without any force stopping or slowing it.

All people are subject to the force due to gravity, which on Earth is about:
#F_"gravity"~~9.8*m# where #m=#mass (in kg) and #F# in Newton.

Normally the Normal Force of the floor we stand on gives a reactive force to keep us from falling through the floor.

If there is nothing in our way - not even air resistance - this force will accelerate us toward the center of the Earth. Since the force will be greater with a greater mass, the acceleration in all cases will be the same:
This is called #g#, it varies a bit according to where you are on the planet, but it is around #9.8 m//s^2#
Which means that every second your speed goes up by that amount, which means that you will reach a speed of #~~50m/s# in 5 seconds (and you have fallen #~~125m#)