Calculating Displacement with Friction and Air Resistance

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Homework Help Overview

The problem involves a car rolling down a hill with an initial velocity and then experiencing forces due to friction and air resistance as it comes to a stop. The subject area includes dynamics and energy conservation principles.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • The original poster attempts to calculate the distance the car travels before stopping by considering kinetic energy and friction. Some participants question the calculations and suggest clarifying the impact of drag force on the overall motion.

Discussion Status

Participants are actively discussing the calculations related to kinetic energy and forces acting on the car. There is a suggestion to reevaluate the methodology by considering both friction and drag forces together. No consensus has been reached yet, and the discussion is ongoing.

Contextual Notes

The original poster has a deadline for homework submission, which adds urgency to the discussion. There is also a mention of specific values such as the mass of the car and the coefficients involved, which may influence the calculations.

ImAlwaysConfu
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Homework Statement



A car is rolling down a hill, it has a velocity of 54.22m/sec at the bottom of the hill. When it reaches the bottom of the hill, a fan begins to blow on it causing a drag force of 250N. Also, the tires create a friction coefficient of .1. The car eventually stops due to the Drag Force/Friction. Calculate how far the car will travel before stopping.



I can't figure out how to take into account the drag force. I know that before taking drag force into account, the car can travel 27.66m. I'm not sure if that helps or not. All I need to know is what formula to use and where I implement the drag force! Also, my homework is due TOMORROW AT 3PM EST. Any help before then will be awesome.
 
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How did you come to the 27.66 m? show your calcs without the drag force and I'll help with implementing the drag force...
 
First, I calculated for the Kinetic Energy which would be 1/2mv^2. 1/2(1700kg)(54.22m/sec) = 46,087J. Next, I calculated the impact friction would have: f=u(coeficcient of friction)F .1(1700)(9.8) = 1,666N. Then I calculted the work that would be done: Work = F(displacement) 46087J = 1,666N(displacement) then I divided 46087 by 1666 and came with 27.66M. If this is incorrect, could you tell me how to do it please? Thanks!
 
I think if I tell you that you would realize how easy it is. So you have an object working to the right with kinetic energy = 0.5*mv^2 your answer here is incorrect, do the calculation again... Now what is the total forces working against the vehicle? friction and drag, draw a FBD for your vehicle... Your methodology is good and accurate just combine everything now... The total force on the car is not just friction?
 

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