Calculating Work Homework: Mass 2400kg, Displ. 200m, Vi 26.5m/s, Vf 30m/s

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Homework Help Overview

The problem involves calculating the work done on a car with a mass of 2400 kg, which travels a displacement of 200 m while accelerating from an initial velocity of 26.5 m/s to a final velocity of 30 m/s. Participants are exploring the relevance of the given information and the appropriate formulas to use in this context.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss whether the formula for work should involve kinetic energy changes or if displacement is necessary. Some express confusion about the relevance of the displacement given the velocities provided.

Discussion Status

There are multiple approaches being considered, including using kinetic energy changes and applying Newton's laws with displacement. Some participants suggest that the question may contain redundant information, prompting a discussion about the necessity of all provided data.

Contextual Notes

Participants are questioning the completeness of the problem statement and whether the inclusion of displacement is essential for solving the problem. There is an acknowledgment of the potential for excessive information in the question.

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Homework Statement


calculate work when mass of car is 2400kg and displacement is 200m the car travels at velocity of 26.5m/s then speeds up to 30m/s

Homework Equations


M- 2400 kg
Vi - 26.5m/s
Vf- 30 m/s
D- 200 m

The Attempt at a Solution


I am struggling with figuring out how to solve this problem would i have to use the formula w = Ek - Ek? But theb i don't end up usinh displacement is there no need to use it here? Does the question have too much information given?
 
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Veronica_Oles said:
Does the question have too much information given?
What do you think and why?
 
There are two ways to solve the problem and both give the same answer.
 
Orodruin said:
What do you think and why?
I think that yes u can solve without displacement. Thats the way i make sense of the question Ek final minus Ek initial!
 
Veronica_Oles said:

Homework Statement


calculate work when mass of car is 2400kg and displacement is 200m the car travels at velocity of 26.5m/s then speeds up to 30m/s

Homework Equations


M- 2400 kg
Vi - 26.5m/s
Vf- 30 m/s
D- 200 m

The Attempt at a Solution


I am struggling with figuring out how to solve this problem would i have to use the formula w = Ek - Ek? But theb i don't end up usinh displacement is there no need to use it here? Does the question have too much information given?

use ##W = {1\over 2}m(v_f^2 - v_i^2)##
 
You can also solve it by using the displacement and the equations of motion to calculate the acceleration. Then apply Newtons law to give the force. Then work = force * distance. Gives same answer as calculating the change in KE.
 
Veronica_Oles said:
But theb i don't end up usinh displacement is there no need to use it here?
Have you quoted the whole question, word for word? It reads a bit strangely.
If so then I applaud the question setter. It should happen much more often that questions include redundant information. Figuring out which information is useful is a necessary skill in the real world.
 

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