Hiking the Appalachian Trail: A Beginner's Guide

[ayans2495]

Homework Statement

What is the mass of the object?

Relevant Equations

F = ma

 

[ayans2495]

My answer: Horizontal function implies zero net force. Therefore, weight is 160 N. Thus, mass is 16 kg such that the acceleration due to gravity is 9.8 N/kg. Am I right?

 

[Delta2]

Your answers are correct but your reasoning is not entirely correct or it is incomplete I would say. The part of the graph where it becomes horizontal doesn't necessarily imply that the net force is zero, however it is implying it in this specific case of drag force being constant. Why? What's the special thing about drag force and how this combined with Newton's second law implies that the net force is zero.

 

[Delta2]

You haven't answer question 25 btw but ok its fairly easy after answering the first two questions.