Odpowiedź :
[tex]Dane:\\ h_0=20m\\ h=5m\\ g=10\frac{m}{s^2}\\ Oblicz:\\ v=?\\ Rozwiazanie:\\ Ep_0=Ep+Ek\\\\\ mgh_0=mgh+\frac{1}{2}mv^2\\\\ 2mgh_0=2mgh+mv^2\\\\ 2gh_0=2gh+v^2\\\\ v^2=2gh_0-2gh\\\\ v=\sqrt{2gh_0-2gh}\\\\ v=\sqrt{2*10*20-2*10*5}\\\\ v=\sqrt{400-100}\\\\ v=\sqrt{300}\\\\ v\approx 17,32\frac{m}{s} [/tex]
dane:
H = 20 m
h = 5 m
g = 10 m/s²
szukane:
v = ?
H - h = gts²/2
ts = √[2(H-h)/g]
v = g * ts
v = g * √[2(H-h)/g]
v = √[2(H-h)/g] = √[2*(20m-5m)/10m/s²] = √(300m²/s²) = √(25*12) m/s
v = 5√12 m/s
v ≈17,32 m/s
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