Question Number 198869 by Tawa11 last updated on 25/Oct/23
Commented by mr W last updated on 25/Oct/23
$$\mathrm{26}.\mathrm{8}\:\mathrm{cos}\:\mathrm{10}°\neq\mathrm{28}.\mathrm{2}\:\mathrm{cos}\:\mathrm{20}° \\ $$$$\Rightarrow{something}\:{in}\:{question}\:{is}\:{wrong}! \\ $$
Commented by Tawa11 last updated on 25/Oct/23
$$\mathrm{Ohh}. \\ $$$$\mathrm{Thanks}\:\mathrm{sir}. \\ $$
Answered by mr W last updated on 25/Oct/23
Commented by mr W last updated on 25/Oct/23
$${u}=\mathrm{26}.\mathrm{8}\:{m}/{s} \\ $$$${v}=\mathrm{28}.\mathrm{1}\:{m}/{s} \\ $$$${h}=\frac{{v}^{\mathrm{2}} −{u}^{\mathrm{2}} }{\mathrm{2}{g}}=\frac{\mathrm{28}.\mathrm{1}^{\mathrm{2}} −\mathrm{26}.\mathrm{8}^{\mathrm{2}} }{\mathrm{2}×\mathrm{9}.\mathrm{81}}=\mathrm{3}.\mathrm{64}\:{m} \\ $$$${t}=\frac{{v}\:\mathrm{sin}\:\mathrm{20}°+{u}\:\mathrm{sin}\:\mathrm{10}°}{{g}} \\ $$$$\:\:=\frac{\mathrm{28}.\mathrm{1}\:\mathrm{sin}\:\mathrm{20}°+\mathrm{26}.\mathrm{8}\:\mathrm{sin}\:\mathrm{10}°}{\mathrm{9}.\mathrm{81}}=\mathrm{1}.\mathrm{45}\:{s} \\ $$$${L}=\left({u}\:\mathrm{cos}\:\mathrm{10}°\right){t}=\mathrm{26}.\mathrm{8}\:\mathrm{cos}\:\mathrm{10}°\:\mathrm{1}.\mathrm{45} \\ $$$$\:\:\:=\mathrm{38}.\mathrm{27}\:{m} \\ $$
Commented by Tawa11 last updated on 25/Oct/23
$$\mathrm{Thanks}\:\mathrm{sir}. \\ $$$$\mathrm{God}\:\mathrm{bless}\:\mathrm{you}\:\mathrm{sir}. \\ $$$$\mathrm{I}\:\mathrm{appreciate}\:\mathrm{your}\:\mathrm{time}. \\ $$