Help Needed: Troubleshooting a Stream Insect Motion Problem

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Homework Help Overview

The problem involves a water insect's motion in a stream, focusing on its ability to maintain a position by darting upstream and drifting downstream. The context includes relative velocity concepts and the effects of current on the insect's movement.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the concept of relative velocity and its application to the insect's motion. Some express uncertainty about how to approach parts of the problem, particularly regarding the equations and methods needed to find the average velocity and distances involved.

Discussion Status

The discussion includes various attempts to clarify the problem and explore different methods for solving it. Some participants have provided formulas and suggested ways to think about the problem, while others are still seeking direction and expressing confusion about the calculations.

Contextual Notes

Participants mention the need for attempts to be shown and question assumptions about the insect's motion relative to the water and shore. There is an indication of imposed homework rules regarding the level of assistance that can be provided.

asloudascanbe
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I've been having difficulty with this problem and can't seem to find where to start. Any help would really be appreciated.

A water insect maintains an average position on the surface of a stream by darting upstream (against the current) then drifting downstream (with the current) to its original position. The current in the stream is 0.540 m/s relative to the shore, and the skater darts upstream 0.510 m (relative to a spot on shore) in 0.770 s during the first part of its motion. Take upstream as the positive direction.
(a) Determine the velocity of the insect relative to the water (i) during its dash upstream

(b) How far upstream relative to the water does the insect move during one cycle of this motion?
m
(c) What is the average velocity of the insect relative to the water?
m/s
 
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Do you know what relative velocity is? You have to show some attempt.

Suppose the skater is still wrt a point on the shore. But the water is flowing past it. What do you think the relative velo of the insect is wrt the flowing water?
 
I don't know how to solve b and c. I don't even know where to start. can anyone point me in the right direction? a formula or some way to think of it other then the way the question states it. I figured out A finally but I never know what equation to use.
 
I thought in order to solve part C. I had to do this:

square root of (.510/.770)^2 + (.540)^2 then divide that answer by 2 to find the average. What did I do wrong?
 
Use this formula: v_ab = va - vb, where v_ab denotes the relative velo of a with respect to b, va and vb are velocities of a and b wrt ground respectively.

Using this, can you find the ans to (a)? Use proper signs.
 
I found the answers to each part but part C. The formula from shooting star is how I found part A. So why would you not add the velocities of the insect relative to the water and divide by 2 in order to find the average velocity of the bug relative to the water for part c?
 
First think about this: what is the averege velocity of the insect wrt the shore?
 

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