Question and Answers Forum

All Questions      Topic List

None Questions

Previous in All Question      Next in All Question      

Previous in None      Next in None      

Question Number 3314 by Filup last updated on 10/Dec/15

Why is it that:  v^→ =(dx^→ /dt) ⇒ x^→ =∫ v^→  dt  a^→ =(d^2 x^→ /dt^2 )=(dv^→ /dt)  v=velocity  x=distance  a=accelerstion  t=time    Why are the formulas for distance,  velocity and acceleration derivatives  of each other?

$$\mathrm{Why}\:\mathrm{is}\:\mathrm{it}\:\mathrm{that}: \\ $$$$\overset{\rightarrow} {{v}}=\frac{{d}\overset{\rightarrow} {{x}}}{{dt}}\:\Rightarrow\:\overset{\rightarrow} {{x}}=\int\:\overset{\rightarrow} {{v}}\:{dt} \\ $$$$\overset{\rightarrow} {{a}}=\frac{{d}^{\mathrm{2}} \overset{\rightarrow} {{x}}}{{dt}^{\mathrm{2}} }=\frac{{d}\overset{\rightarrow} {{v}}}{{dt}} \\ $$$${v}={velocity} \\ $$$${x}={distance} \\ $$$${a}={accelerstion} \\ $$$${t}={time} \\ $$$$ \\ $$$$\mathrm{Why}\:\mathrm{are}\:\mathrm{the}\:\mathrm{formulas}\:\mathrm{for}\:\mathrm{distance}, \\ $$$$\mathrm{velocity}\:\mathrm{and}\:\mathrm{acceleration}\:\mathrm{derivatives} \\ $$$$\mathrm{of}\:\mathrm{each}\:\mathrm{other}? \\ $$

Commented by Filup last updated on 10/Dec/15

x^→ =u^→ t+(1/2)a^→ t^2   ↓  v^→ =u^→ +a^→ t  ↓  a^→ =a^→

$$\overset{\rightarrow} {{x}}=\overset{\rightarrow} {{u}t}+\frac{\mathrm{1}}{\mathrm{2}}\overset{\rightarrow} {{a}t}^{\mathrm{2}} \\ $$$$\downarrow \\ $$$$\overset{\rightarrow} {{v}}=\overset{\rightarrow} {{u}}+\overset{\rightarrow} {{a}t} \\ $$$$\downarrow \\ $$$$\overset{\rightarrow} {{a}}=\overset{\rightarrow} {{a}} \\ $$

Answered by prakash jain last updated on 10/Dec/15

velocity: rate of change in displacement  v^→ =((Δx^→ )/(Δt))  This is same as slope of distance time graph.  Taking Δt infinitesimally small to get  instantatenous velocity  v^→ =lim_(Δt→0) ((Δx^→ )/(Δt))=(dx^→ /dt)  v^→ =(dx^→ /dt)  Same applied for acceleration   a^→ =((Δv^→ )/(Δt))   instantaneous acceeration  a^→ =(dv^→ /dt)

$${velocity}:\:\mathrm{rate}\:\mathrm{of}\:\mathrm{change}\:\mathrm{in}\:\mathrm{displacement} \\ $$$$\overset{\rightarrow} {{v}}=\frac{\Delta\overset{\rightarrow} {{x}}}{\Delta{t}} \\ $$$$\mathrm{This}\:\mathrm{is}\:\mathrm{same}\:\mathrm{as}\:\mathrm{slope}\:\mathrm{of}\:\mathrm{distance}\:\mathrm{time}\:\mathrm{graph}. \\ $$$$\mathrm{Taking}\:\Delta{t}\:\mathrm{infinitesimally}\:\mathrm{small}\:\mathrm{to}\:\mathrm{get} \\ $$$$\mathrm{instantatenous}\:\mathrm{velocity} \\ $$$$\overset{\rightarrow} {{v}}=\underset{\Delta{t}\rightarrow\mathrm{0}} {\mathrm{lim}}\frac{\Delta\overset{\rightarrow} {{x}}}{\Delta{t}}=\frac{{d}\overset{\rightarrow} {{x}}}{{dt}} \\ $$$$\overset{\rightarrow} {{v}}=\frac{{d}\overset{\rightarrow} {{x}}}{{dt}} \\ $$$$\mathrm{Same}\:\mathrm{applied}\:\mathrm{for}\:\mathrm{acceleration}\: \\ $$$$\overset{\rightarrow} {{a}}=\frac{\Delta\overset{\rightarrow} {{v}}}{\Delta{t}}\: \\ $$$$\mathrm{instantaneous}\:\mathrm{acceeration} \\ $$$$\overset{\rightarrow} {{a}}=\frac{{d}\overset{\rightarrow} {{v}}}{{dt}} \\ $$

Terms of Service

Privacy Policy

Contact: info@tinkutara.com