1.
[tex]dane:\\m = 10 \ kg\\v_{o} = 0\\t = 4 \ s\\a = 5\frac{m}{s^{2}}\\szukane:\\W = ?\\\\W = F\cdot s\\\\F = m\cdot a = 10 \ kg\cdot5\frac{m}{s^{2}} = 50 \ N\\\\s = \frac{1}{2}at^{2} = \frac{1}{2}\cdot5\frac{m}{s^{2}}\cdot(4 \ s)^{2} = 40 \ m\\\\W = 50 \ N\cdot40 \ m = 200 \ J[/tex]
2.
[tex]dane:\\W = 80 \ kJ = 80 \ 000 \ J\\F= F_{T}=800 \ N \ - \ ruch \ jednostajny \ - \ I \ zasada \ dynamiki\\szukane:\\s = ?\\\\W = F\cdot s \ \ /:F\\\\s = \frac{W}{F}\\\\s = \frac{80000 \ J}{800 \ N} = \frac{80000 \ N\cdot m}{800 \ N} = 100 \ m[/tex]
3.
[tex]dane:\\v = 1,5\frac{m}{s}\\F = 400 \ N\\t = 2 \ h = 2\cdot3600 \ s = 7200 \ s\\szukane:\\W = ?\\\\P = \frac{W}{t} \ \ \rightarrow \ \ W = P\cdot t\\i\\P = \frac{F\cdot s}{t} = F\cdot v\\\\W = F\cdot v\cdot t\\\\W = 400 \ N\cdot1,5\frac{m}{s}\cdot7200 \ s\\\\W = 4 \ 320 \ 000 \ J = 4 \ 320 \ kJ[/tex]
4.
[tex]dane:\\m = 1 \ kg\\\Delta h = 2 \ m - 1 \ m = 1 \ m\\g = 10\frac{N}{kg}\\szukane:\\\Delta E_{p} = ?\\\\\Delta E_{p}= m\cdot g\cdot\Delta h\\\\\Delta E_{p} = 1 \ kg\cdot10\frac{N}{kg}\cdot 1 \ m\\\\\Delta E_{p} = 10 \ J[/tex]