Question Number 125048 by bemath last updated on 08/Dec/20
$${It}\:{takes}\:{a}\:{force}\:{of}\:\mathrm{19},\mathrm{000}\:{lb}\:{to} \\ $$$${compress}\:{a}\:{spring}\:{from}\:{its}\:{free} \\ $$$${height}\:{of}\:\mathrm{15}\:{in}\:{to}\:{its}\:{fully}\: \\ $$$${compressed}\:{height}\:{of}\:\mathrm{10}\:{in}.\:{How} \\ $$$${much}\:\:{work}\:{does}\:{it}\:{take}\:{to}\: \\ $$$${compress}\:{the}\:{spring}\:{the}\:{first}\:{in}? \\ $$$$\left({a}\right)\:\mathrm{1900}\:{in}.−{lb} \\ $$$$\left({b}\right)\:\mathrm{950}\:{in}.−{lb} \\ $$$$\left({c}\right)\:\mathrm{3800}\:{in}.−{lb} \\ $$$$\left({d}\right)\:\mathrm{190},\mathrm{000}\:{in}.−{lb} \\ $$
Commented by mr W last updated on 08/Dec/20
$${W}=\frac{\mathrm{1}}{\mathrm{2}}×\mathrm{1}×\left(\frac{\mathrm{1}}{\mathrm{10}}×\mathrm{19000}\right)=\mathrm{950}\:{in}.−{lb} \\ $$$$\Rightarrow{answer}\:\left({b}\right) \\ $$