Odpowiedź:
[tex]1. \\dane:\\F=50N\\s=2km=2~000m\\\\szukane:W=F\cdot s\\\\rozwiazanie:\\W=50N\cdot 2~000m=100~000J=0,1MJ\\\\2. \\m=9t=9~000kg\\W=45MJ=45~000~000J\\\\szukane:\\s=?\\W=F\cdot s=m\cdot g\cdot s\\s=\frac{W}{m\cdot g}\\\\rozwiazanie:\\s=\frac{45~000~000J}{9~000kg\cdot 10\frac{m}{s^2}}=500m\\[/tex]
[tex]3. \\dane:\\t=1min=60s\\\Delta E=3,6kJ=3~600J\\\\szukane:\\P=\frac{W}{t}\\W=\Delta E\\\\rozwiazanie:\\P=\frac{3~600J}{60s}=60W\\\\4. \\dane:\\h=300m\\t=8min=480s\\m=70kg\\\\szukane:\\P=\frac{W}{t}\\W=\Delta E_p\\\Delta E_p=m\cdot g\cdot h\\P=\frac{m\cdot g\cdot h}{t}\\\\rozwiazanie:\\P=\frac{70kg\cdot 10\frac{m}{s^2}\cdot 300m}{480s}=437,5W[/tex]
Wyjaśnienie:
