[latex]V_{o}=100frac{m}{s} \ V_{k}=0frac{m}{s} \ a) \ left { {{V_{k}=V_{o} - at} atop {S_{k}=S_{o}+V_{o}t-frac{at^{2}}{2}}} ight \ [/latex] [latex]left { {{at=V_{o} o a=frac{V_{o}}{t}} atop {S=V_{o}t-frac{at^{2}}{2}}} ight \ S=V_{o}t-frac{frac{V_{o}}{t} cdot t^{2}}{2} \ S=V_{o}t-frac{V_{o}t}{2} \ [/latex] [latex]S=t[V_{o}-frac{V_{o}}{2}] \ t=frac{S}{V_{o}-frac{V_{o}}{2}}=frac{500m}{100frac{m}{s}-50frac{m}{s}}=frac{500m}{50frac{m}{s}}=10s \ [/latex] [latex]a=frac{ Delta V }{ Delta t} = frac{-100frac{m}{s}}{10s}=-10frac{m}{s^{2}}[/latex]
dane: vo = 100 m/s s = 500 m szukane: a) t = ? b) -a = ? a) s = vot - at^2/2 a = (vk-vo)/t = vo/t s = vot - vot x t/t^2/2 I*2 2vot - vot = 2s vot = 2s /:vo t = 2s/vo = 2 x 500m/100m/s t = 10 s ====== b) -a = dv/dt = 100m/s/10s -a = 10 m/s2 ===========
