Question Number 65414 by mr W last updated on 29/Jul/19
Commented by mr W last updated on 25/Feb/21
$${a}\:{ball}\:{is}\:{thrown}\:{from}\:{point}\:{A}\:{with} \\ $$$${speed}\:{u}\:{and}\:{at}\:{an}\:{angle}\:\theta.\:{it}\:{strikes} \\ $$$${at}\:{a}\:{point}\:{on}\:{the}\:{inclined}\:{surface}\: \\ $$$${and}\:{returns}\:{back}\:{to}\:{its}\:{start}\:{point}. \\ $$$${if}\:{the}\:{coefficient}\:{of}\:{restitution}\:{is}\:{e}, \\ $$$${find}\:{u}\:{in}\:{terms}\:{of}\:\theta.\:{what}\:{is}\:\theta\:{such} \\ $$$${that}\:{u}\:{is}\:{minimum}? \\ $$