Question

Care este raportul dintre energia cinetica si pontetiala la inaltimea de 5 cm de la sol, daca corpul cade fara viteza initiala de la inaltimea de 20 cm?
Va rooog!Dau coronita.

Answer 1

[tex]Se~da:\\ \\ h_{1}=5cm=0,05m \\ \\ h=20cm=0,2m \\ \\ \frac{Ec_{1}}{Ep_{1}}=?\\ \\ [/tex]

[tex]Formule:\\ \\ \frac{Ec_{1}}{Ep_{1}}=\frac{\frac{m\times v_{1}^{2}}{2}}{m\times g \times h_{1}}\\ \\ \frac{Ec_{1}}{Ep_{1}}=\frac{m\times v_{1}^{2}}{2\times m \times g \times h_{1}}\\ \\ \frac{Ec_{1}}{Ep_{1}}=\frac{ v_{1}^{2}}{2 \times g \times h_{1}}\\ \\ \\ Ec_{1}+Ep_{1}=Ep\\ \\ \frac{m \times v_{1}^{2}}{2}+m \times g \times h_{1}=m \times g \times h\\ \\ v_{1}^{2}=2 \times g \times h-2 \times g \times h_{1}\\ \\ v_{1}^{2}=2 \times g \times(h-h_{1})\\ \\ \\ [/tex]


[tex]\frac{Ec_{1}}{Ep_{1}}=\frac{2 \times g \times(h-h_{1})}{2 \times g \times h_{1}}\\ \\ \frac{Ec_{1}}{Ep_{1}}=\frac{h-h_{1}}{h_{1}}\\ \\ \\ Calcule:\\ \\ \frac{Ec_{1}}{Ep_{1}}=\frac{0,2-0,05}{0,05}=3[/tex]