Question Number 50973 by Necxx last updated on 22/Dec/18
Answered by mr W last updated on 22/Dec/18
$${see}\:{Q}\mathrm{50913}. \\ $$$${t}_{\mathrm{1}} =\mathrm{2}{e}\sqrt{\frac{\mathrm{2}{h}}{{g}}}=\mathrm{2}\left(\frac{\mathrm{3}}{\mathrm{4}}\right)\sqrt{\frac{\mathrm{2}×\mathrm{20}}{\mathrm{10}}}=\mathrm{3}\:{seconds} \\ $$
Commented by Necxx last updated on 25/Dec/18
$${oh}....\:{i}\:{have}\:{not}\:{come}\:{across}\:{this} \\ $$$${formula}.{Its}\:{really}\:{precise}.{Thanks} \\ $$