Question Number 190634 by Mastermind last updated on 07/Apr/23
$$\mathrm{The}\:\mathrm{volume}\:\mathrm{of}\:\mathrm{a}\:\mathrm{right}\:\mathrm{circular}\:\mathrm{cone} \\ $$$$\mathrm{is}\:\mathrm{5litres}.\:\mathrm{Calculate}\:\mathrm{the}\:\mathrm{volume}\:\mathrm{of} \\ $$$$\mathrm{the}\:\mathrm{part}\:\mathrm{into}\:\mathrm{which}\:\mathrm{the}\:\mathrm{cone}\:\mathrm{is} \\ $$$$\mathrm{divided}\:\mathrm{by}\:\mathrm{a}\:\mathrm{plane}\:\mathrm{parallel}\:\mathrm{to}\:\mathrm{the} \\ $$$$\mathrm{base}\:\mathrm{one}−\mathrm{third}\:\mathrm{of}\:\mathrm{the}\:\mathrm{way}\:\mathrm{down} \\ $$$$\mathrm{from}\:\mathrm{the}\:\mathrm{vertex}\:\mathrm{to}\:\mathrm{the}\:\mathrm{base}\:\mathrm{giving} \\ $$$$\mathrm{your}\:\mathrm{answer}\:\mathrm{to}\:\mathrm{the}\:\mathrm{nearest}\: \\ $$$$\mathrm{millimetres}. \\ $$$$ \\ $$$$ \\ $$$$\mathrm{Help}! \\ $$
Commented by JDamian last updated on 08/Apr/23
The right cone volume is in litres but the other volume is in milimetres?
Commented by Mastermind last updated on 08/Apr/23
$$\mathrm{Thank}\:\mathrm{you}\:\mathrm{but}\:\mathrm{i}\:\mathrm{need}\:\mathrm{full}\:\mathrm{workings} \\ $$
Commented by Mastermind last updated on 08/Apr/23
$$\mathrm{The}\:\mathrm{volume}\:\mathrm{of}\:\mathrm{a}\:\mathrm{right}\:\mathrm{circular}\:\mathrm{cone} \\ $$$$\mathrm{is}\:\mathrm{5litres}.\:\mathrm{Calculate}\:\mathrm{the}\:\mathrm{volume}\:\mathrm{of} \\ $$$$\mathrm{the}\:\mathrm{part}\:\mathrm{into}\:\mathrm{which}\:\mathrm{the}\:\mathrm{cone}\:\mathrm{is} \\ $$$$\mathrm{divided}\:\mathrm{by}\:\mathrm{a}\:\mathrm{plane}\:\mathrm{parallel}\:\mathrm{to}\:\mathrm{the} \\ $$$$\mathrm{base}\:\mathrm{one}−\mathrm{third}\:\mathrm{of}\:\mathrm{the}\:\mathrm{way}\:\mathrm{down} \\ $$$$\mathrm{from}\:\mathrm{the}\:\mathrm{vertex}\:\mathrm{to}\:\mathrm{the}\:\mathrm{base}\:\mathrm{giving} \\ $$$$\mathrm{your}\:\mathrm{answer}\:\mathrm{to}\:\mathrm{the}\:\mathrm{nearest}\: \\ $$$$\mathrm{millimetres}. \\ $$$$ \\ $$$$ \\ $$$$\mathrm{I}\:\mathrm{need}\:\mathrm{the}\:\mathrm{full}\:\mathrm{workings} \\ $$
Commented by mr W last updated on 08/Apr/23
$${what}\:{do}\:{you}\:{expect}\:{as}\:{full}\:{workings}? \\ $$$${you}\:{have}\:\mathrm{5}\:{litres}\:{water}\:{and}\:{you}\:{give} \\ $$$${one}\:\mathrm{27}{th}\:{of}\:{the}\:{water}\:{to}\:{your}\:{friend}. \\ $$$${how}\:{much}\:{water}\:{does}\:{he}\:{get}? \\ $$$${better}\:{you}\:{check}\:{your}\:{question}\:{at} \\ $$$${first}.\:\:{you}\:{can}\:{not}\:{give}\:{your}\:{friend} \\ $$$${some}\:{millimeters}\:{water}.\:{this}\:{is}\:{like}, \\ $$$${when}\:{i}\:{ask}:\:{if}\:{your}\:{father}\:{is}\:\mathrm{45}\:{years} \\ $$$${old}\:{and}\:{your}\:{age}\:{is}\:{one}\:{third}\:{of}\:{his}, \\ $$$${calculate}\:{your}\:{age}\:{and}\:{give}\:{your} \\ $$$${answer}\:{to}\:{the}\:{nearest}\:{kilogram}. \\ $$
Commented by mr W last updated on 08/Apr/23
$${in}\:{short}:\:{millimeter}\:{is}\:{not}\:{an}\:{unit} \\ $$$${for}\:{volume}! \\ $$
Commented by mr W last updated on 18/Apr/23
$${you}\:{cried}\:{for}\:{full}\:{workings}\:{again} \\ $$$${and}\:{again}.\:{but}\:{when}\:{somebody}\:{really} \\ $$$${gave}\:{you}\:{the}\:{full}\:{workings},\:{you}\: \\ $$$${didn}'{t}\:{show}\:{any}\:{reaction}.\:\:{what}\:{a} \\ $$$${strange}\:{human}! \\ $$
Answered by mr W last updated on 08/Apr/23
Commented by mr W last updated on 08/Apr/23
$${h}_{\mathrm{1}} =\frac{{h}}{\mathrm{3}} \\ $$$$\Rightarrow{r}_{\mathrm{1}} =\frac{{r}}{\mathrm{3}} \\ $$$${V}_{\mathrm{1}} =\frac{\pi{r}_{\mathrm{1}} ^{\mathrm{2}} {h}_{\mathrm{1}} }{\mathrm{3}} \\ $$$${V}=\frac{\pi{r}^{\mathrm{2}} {h}}{\mathrm{3}} \\ $$$$\frac{{V}_{\mathrm{1}} }{{V}}=\left(\frac{{r}_{\mathrm{1}} }{{r}}\right)^{\mathrm{2}} \left(\frac{{h}_{\mathrm{1}} }{{h}}\right)=\left(\frac{\mathrm{1}}{\mathrm{3}}\right)^{\mathrm{2}} =\frac{\mathrm{1}}{\mathrm{27}} \\ $$$$\Rightarrow{V}_{\mathrm{1}} =\frac{{V}}{\mathrm{27}}=\frac{\mathrm{5}\:{l}}{\mathrm{27}}=\frac{\mathrm{5}×\mathrm{10}^{\mathrm{6}} }{\mathrm{27}}\approx\mathrm{185}\:\mathrm{185}\:{mm}^{\mathrm{3}} \\ $$
Commented by Mastermind last updated on 26/Apr/23
$$\mathrm{Thank}\:\mathrm{you}\:\mathrm{so}\:\mathrm{much} \\ $$
Answered by talminator2856792 last updated on 09/Apr/23
$$\:\:\mathrm{the}\:\mathrm{volume}\:\mathrm{will}\:\mathrm{be}\:\frac{\mathrm{5}}{\mathrm{27}}\:\mathrm{litres}.\:\: \\ $$