posted by cody on .
A rock of mass 32 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 275 N. What is the magnitude of the acceleration of the rock?
(Weight - 275 N)/Mass = acceleration
Weight = 313.6 N
a = (313.6-275)/32 = 1.2 m/s^2
This accleration can only apply for an instant
Actually, acceleration will decrease and velocity and air resistance will increase until a limiting velocity is reached and acceleration becomes zero. This is a misleading problem.