1.
[tex]Dane:\\m = 800 \ kg\\v_1 = 160\frac{km}{h}\\t = 2 \ s\\v_2 = 214\frac{km}{h}\\Szukane:\\a = ?\\F_{w} = ?[/tex]
Rozwiązanie
Przyspieszenie:
[tex]a = \frac{\Delta v}{t}\\\\\Delta v = v_2-v_1 = (216-160)\frac{km}{h} = 50\frac{km}{h} = 50\cdot\frac{1000 \ m}{3600 \ s} = 15\frac{m}{s}\\\\a = \frac{15\frac{m}{s}}{2 \ s}\\\\\boxed{a = 7,5\frac{m}{s^{2}}}[/tex]
Siła wypadkowa:
[tex]F_{w} = m\cdot a\\\\F_{w} = 800 \ kg\cdot 7,5\frac{m}{s^{2}}\\\\\boxed{F_{w} = 6 \ 000 \ N = 6 \ kN}[/tex]
2.
[tex]Dane:\\m = 250 \ t = 250 \ 000 \ kg\\F_{o} = 15 \ kN\\a = 0,6\frac{m}{s^{2}}=0,6\frac{N}{kg}\\Szukne:\\F = ?[/tex]
Rozwiązanie
Z II zasady dynamiki Newtona:
[tex]F_{w} = m\cdot a\\\\F_{w} = 250 \ 000 \ kg\cdot0,6\frac{N}{kg}= 150 \ 000 \ N = 150 \ kN\\\\\\F_{w} = F-F_{o}\\\\F = F_{w}+F_{o}\\\\F = 150 \ kN + 15 \ kN\\\\\boxed{F = 165 \ kN}[/tex]
