A rock of mass 44 kg accidentally breaks loose from the edge of a cliff and falls straight down. The magnitude of the air resistance that opposes its downward motion is 258 N. What is the magnitude of the acceleration of the rock?

2 answers

Fn = Fr - Fa,
Fn = 32*9.8 - 258 = 55.6 N.=Net force.

a = Fn/m = 55.6 / 32 = 1.74 m/s^2.
Correction: In each Eq, replace 32 with 44 and recalculate.