2/15.
[tex]dane:\\m = 2,4 \ t = 2,4\cdot1000 \ kg = 2 \ 400 \ kg\\a = 2\frac{m}{s^{2}}\\szukane:\\F = ?\\\\\\Z \ II \ zasady \ dynamiki:\\\\a = \frac{F}{m} \ \ /\cdot m\\\\F = m\cdot a\\\\F = 2400 \ kg\cdot2\frac{m}{s^{2}}\\\\\underline{F = 4 \ 800 \ N = 4,8 \ kN}\\\\(1 \ kN = 1000 \ N)[/tex]
5/15.
[tex]dane:\\v_{o} = 0\\h = 2,45 \ m\\g = 10\frac{m}{s^{2}}\\szukane:\\t = ?\\\\\\s = \frac{at^{2}}{2}\\\\a = g, \ \ s = h\\\\h = \frac{gt^{2}}{2} \ \ /\cdot\frac{2}{g}\\\\t^{2} = \frac{2h}{g}\\\\t = \sqrt{\frac{2h}{g}}\\\\t = \sqrt{\frac{2\cdot2,45 \ m}{10\frac{m}{s^{2}}}} = \sqrt{0,49 \ s^{2}}\\\\\underline{t = 0,7 \ s}[/tex]
