physics.!!!?

Question

A 2.2 kg purse is dropped from the top of the Leaning Tower of Pisa and falls 55 m before reaching the ground with a speed of 30 m/s. What was the average force of air resistance?
??N upward

Answer 1

We know that gravitational acceleration is g= 9.81m/s^2 so we have to compute what was the actual acceleration.

h=0.5at^2
V=at so t=V/a we have
h=0.5 a (V/a)^2
h= 0.5 V^2 /a
a= 0.5 V^2 /h
a= 0.5 (30)^2 / 55 = 8.18 m/s^2

F=m(g-a)=2.2(9.81-8.18)=
F=3.59 N