Why do we use area under the curve to find displacement in particle motion?

AI Thread Summary
The discussion focuses on using the area under the curve to calculate displacement in particle motion. A participant calculated the total distance traveled by a particle, correcting for its initial position. They explored alternative methods, including using velocity equations and plotting speed versus time to find the area under the curve. The area under the curve represents the distance covered, particularly in cases with simple geometric shapes like triangles. This method simplifies the calculation of displacement in particle motion scenarios.
rudransh verma
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Homework Statement
The displacement of a particle moving in straight line is given by ##s=6+12t-2t^2##. The distance covered by particle in first 5sec. Units are in meters and sec.
Relevant Equations
##v=\frac{ds}{dt}##
I calculated v=0 at t=3. s(3) =24 m. s(5)=16 m. So reverse distance that the particle travelled=24-16=8 m. So total distance =24+8=32 m.
 
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But s=6 at t=0. Did you take this into account?
 
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phyzguy said:
But s=6 at t=0. Did you take this into account?
O yes! I thought the position is origin at t=0. So it will be 32-6=26 meters. Thanks. Is there any other way to do it ?
 
Well, you could take the velocity, which is v = ds/dt = 12 - 4t, and then find \int_0^5 |v| dt = 26.
 
rudransh verma said:
Is there any other way to do it ?
You can also plot speed vs. time and find the area under the curve (see below) which is easy in this case of two right triangles. This is the geometric equivalent of what @phyzguy suggested in post #4.

Vee_vs_Tee_2.png
 
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kuruman said:
You can also plot speed vs. time and find the area under the curve
Ok! By the way why we use area under the curve thing.
Is it because finding area under the curve (integral) give the distance covered and we use the same concept of finding the area except it’s easy here because there are two triangles?
 
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rudransh verma said:
Ok! By the way why we use area under the curve thing.
Is it because finding area under the curve (integral) give the distance covered and we use the same concept of finding the area except it’s easy here because there are two triangles?
Yes.
 
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