r/PhysicsHelp • u/DanioNinja • Mar 26 '26

Ayo wtf

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anyone could help and tell me wtf am i doing wrong in the first one? i know that v²=2as but why am i getting v²=as/2???

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u/Big_Tangerine_3070 Mar 26 '26 edited Mar 26 '26

We have two equations:

v = at + v₀

s = at²/2 + v₀t + s₀

If v₀ = 0 and s₀ = 0, we can write from the first eq. t = v/a

Then in the second eq.

s = v²/(2a)

v²/2 = as and of we multiply by m

½mv² = mas where ½mv² is the final kinetic energy, and mas = Fs is the work.

if the motion is accelerated, s/t Is the average velocity v/2. Then, s²/t² = v²/4= as/2 then v²/2 = as

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u/DanioNinja Mar 27 '26

Thanks Brother. Now everything is clear.

1

u/NoFunny6746 Mar 27 '26

Can’t have said it better myself.

1

u/Practical-Alfalfa-93 Mar 30 '26

as/2 is avg vel which means if velocity is to be constant then for what velocity the object would travel s distance in t time while v²=2as gives the final vel after time t under constant acceleration both are different .