Last one I PROMISE gravity question

[ladolce]

Homework Statement

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 242 N. What is the magnitude of the acceleration of the rock?

Homework Equations

F=ma (?)

The Attempt at a Solution

I just did 242 N/32 kg and thought that was good but apparently that's not right?

 

[malawi_glenn]

The SUM of all forces is: F = ma

so you find the force acting on the rock directed down wards, and upwards; the you will get the sum of the force acting on the rock.

 

[HallsofIvy]

There is a downward force of mg and an upward force of 242 N.

 

[ladolce]

that's what i thought of later too, but how much force does gravity exert in N?

 

[ladolce]

OK, I got the answer.
Thank you.