Thread: What was the average force of air resistance?

A 2.1 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 28 m/s.

What is the initial PE, and the final KE?

Kinetic Energy in J if m is in kg and V is in m/s
KE = ½mV²
Potential Energy in J
PE = mgh
g is the acceleration of gravity 9.8 m/s²

Ke = ½2.1?28² = 823.2 J
PE = (2.1)(9.8)(55) = 1131.9
difference is 308.7 J

Work = Force x distance
308.7 = F x 55
F = 5.61 newtons