Question

Viteza unui automobil este descrisa de formula v = 10t^2 + 3t + 2 (m/s). Gasiti formula care exprima acceleratia acestui automobil. Care este viteza si acceleratia pentru t=2s?

Answer 1

$\vec{a}= \lim_{\Delta t \to 0} \frac{\Delta v}{\Delta t} =\frac{d\vec{v}}{dt}\\ a=\frac{dv}{dt}=(10t^2+3t+2)'=2*10t+3=20t+3=>a=20t+3 (m/s^2)\\t=2s=>v(2)=10*2^2+3*2+2=10*4+6+2=40+8=48 =>v(2)=48 m/s\\a(2)=20*2+3=40+3=43=>a(2)=43 (m/s^2)$