Question and Answers Forum

All Questions      Topic List

Others Questions

Previous in All Question      Next in All Question      

Previous in Others      Next in Others      

Question Number 26634 by tawa tawa last updated on 27/Dec/17

Commented by tawa tawa last updated on 27/Dec/17

Am confused about the direction of the 25N arrow... does it mean (− 20N) ??

$$\mathrm{Am}\:\mathrm{confused}\:\mathrm{about}\:\mathrm{the}\:\mathrm{direction}\:\mathrm{of}\:\mathrm{the}\:\mathrm{25N}\:\mathrm{arrow}...\:\:\mathrm{does}\:\mathrm{it}\:\mathrm{mean}\:\:\:\left(−\:\mathrm{20N}\right)\:?? \\ $$

Answered by mrW1 last updated on 28/Dec/17

F_x =15+10×cos 30+20 cos 30−5 sin 30+25sin 30−30 =−15+30×cos 30+20 sin 30 =−15+30×((√3)/2)+20×(1/2) =15(√3)−5 =5(3(√3)−1) F_y =10×sin 30−20 sin 30+5 cos 30+25 cos 30 =−10×sin 30+30 cos 30 =−10×(1/2)+30×((√3)/2) =−5+15(√3) =5(3(√3)−1) F=(√(F_x ^2 +F_y ^2 ))=5(3(√3)−1)(√2) ≈29.67 N

$${F}_{{x}} =\mathrm{15}+\mathrm{10}×\mathrm{cos}\:\mathrm{30}+\mathrm{20}\:\mathrm{cos}\:\mathrm{30}−\mathrm{5}\:\mathrm{sin}\:\mathrm{30}+\mathrm{25sin}\:\mathrm{30}−\mathrm{30} \\ $$$$=−\mathrm{15}+\mathrm{30}×\mathrm{cos}\:\mathrm{30}+\mathrm{20}\:\mathrm{sin}\:\mathrm{30} \\ $$$$=−\mathrm{15}+\mathrm{30}×\frac{\sqrt{\mathrm{3}}}{\mathrm{2}}+\mathrm{20}×\frac{\mathrm{1}}{\mathrm{2}} \\ $$$$=\mathrm{15}\sqrt{\mathrm{3}}−\mathrm{5} \\ $$$$=\mathrm{5}\left(\mathrm{3}\sqrt{\mathrm{3}}−\mathrm{1}\right) \\ $$$$ \\ $$$${F}_{{y}} =\mathrm{10}×\mathrm{sin}\:\mathrm{30}−\mathrm{20}\:\mathrm{sin}\:\mathrm{30}+\mathrm{5}\:\mathrm{cos}\:\mathrm{30}+\mathrm{25}\:\mathrm{cos}\:\mathrm{30} \\ $$$$=−\mathrm{10}×\mathrm{sin}\:\mathrm{30}+\mathrm{30}\:\mathrm{cos}\:\mathrm{30} \\ $$$$=−\mathrm{10}×\frac{\mathrm{1}}{\mathrm{2}}+\mathrm{30}×\frac{\sqrt{\mathrm{3}}}{\mathrm{2}} \\ $$$$=−\mathrm{5}+\mathrm{15}\sqrt{\mathrm{3}} \\ $$$$=\mathrm{5}\left(\mathrm{3}\sqrt{\mathrm{3}}−\mathrm{1}\right) \\ $$$$ \\ $$$${F}=\sqrt{{F}_{{x}} ^{\mathrm{2}} +{F}_{{y}} ^{\mathrm{2}} }=\mathrm{5}\left(\mathrm{3}\sqrt{\mathrm{3}}−\mathrm{1}\right)\sqrt{\mathrm{2}} \\ $$$$\approx\mathrm{29}.\mathrm{67}\:{N} \\ $$

Commented by tawa tawa last updated on 28/Dec/17

God bless you sir.

$$\mathrm{God}\:\mathrm{bless}\:\mathrm{you}\:\mathrm{sir}. \\ $$

Commented by tawa tawa last updated on 28/Dec/17

But sir the 25N is negative right ??. [− 25N]

$$\mathrm{But}\:\mathrm{sir}\:\mathrm{the}\:\:\mathrm{25N}\:\:\mathrm{is}\:\:\mathrm{negative}\:\mathrm{right}\:??.\:\:\:\:\left[−\:\mathrm{25N}\right] \\ $$

Commented by mrW1 last updated on 28/Dec/17

It is the same as this:

$${It}\:{is}\:{the}\:{same}\:{as}\:{this}: \\ $$

Commented by mrW1 last updated on 28/Dec/17

Commented by tawa tawa last updated on 28/Dec/17

God bless you sir. i really appreciate.

$$\mathrm{God}\:\mathrm{bless}\:\mathrm{you}\:\mathrm{sir}.\:\mathrm{i}\:\mathrm{really}\:\mathrm{appreciate}. \\ $$

Terms of Service

Privacy Policy

Contact: info@tinkutara.com