Engineering Mechanics: Statics & Dynamics (14th Edition)

Published by Pearson
ISBN 10: 0133915425
ISBN 13: 978-0-13391-542-6

Chapter 16 - Planar Kinematics of a Rigid Body - Section 16.5 - Relative-Motion Analysis: Velocity - Problems - Page 358: 72

Answer

$$ V_B=3 \frac{\mathrm{m}}{\mathrm{s}} \rightarrow \\ V_c=0.5864 \mathrm{~m} / \mathrm{s} \rightarrow \\ $$

Work Step by Step

$$ \begin{array}{l} \begin{array}{l} \theta=\tan ^{-1}\left(\frac{3}{4}\right) \rightarrow \theta=36.87^{\circ} \\ \vec{V}_B=V_A+w_{A B D} \hat{k} \hat{r}_{B / A} \\ V_B \hat{\imath}=-4 \hat{\jmath}+w_{A B D} \hat{k}\left(-0.55 \cos 36.87^{\circ} \hat{\imath}+0.55 \operatorname{sen} 36.87^{\circ} \hat{\jmath}\right) \\ V_B \hat{\imath}=-4 \hat{\jmath}-0.44 W_{A B D} \hat{\jmath}-0.33 W_{A B D} \hat{\imath} \\ \hat{\jmath}=\hat{\jmath} \\ 0=-4-0.44 \omega_{A B D} \\ 0.44 w_{A D D}=-4 \\ W_{A B D}=\frac{-4}{0.44} \\ W_{A B D}=-9.09 \\ \sim w_{A B D}=9.09 \frac{\mathrm{rad}}{\mathrm{s}} \circlearrowright \\ \hat{\imath}=\hat{\imath} \\ V_B=-0.33 w_{A B D} \\ V_B=-0.33(-9.09) \\ V_B=3 \frac{\mathrm{m}}{\mathrm{s}} \rightarrow \\ \vec{V}_D=V_B+w_{A B D} \hat{k} \hat{r}_{D / B} \\ \vec{V}_D=3 \hat{\imath}+(-9.09) \hat{k}\left(0.25 \cos 36.87^{\circ} \hat{\imath}-0.25 \operatorname{sen} 36.87^{\circ} \hat{\jmath}\right) \\ \vec{V}_D=3 \hat{\imath} -1.818\hat{\jmath} -1.3635\hat{\imath}\\ \vec{V}_D=1.6364 \hat{\imath}-1.818 \hat{\jmath}\\ \vec{V}_D=V_C+w_{C D E} \hat{k} \hat{r}_{D / C} \\ \end{array}\\ \begin{array}{l} (1.6364 \hat{\imath}-1.818 \hat{\jmath})=V_C \hat{\imath}+W_{C D E} \hat{k}\left(0.4 \cos 30^{\circ} \hat{\imath}+0.4 \operatorname{sen} 30^{\circ} \hat{\jmath}\right) \\ (1.6364 \hat{\imath}-1.818 \hat{\jmath})=v_C \hat{\imath}+0.3464 w_{C D E} \hat{\jmath}-0.2 w_{\operatorname{CDE}} \hat{\imath} \\ \hat{\jmath}=\hat{\jmath} \\ -1.818=0.34642 W_{C D E} \\ w_{C D E}=\frac{-1.818}{0.3464} \\ w_{C D E}=-5.25 \\ \sim w_{\text {CDE }}=5.25 \frac{\mathrm{rad}}{\mathrm{s}} \circlearrowright \\ \hat{\imath}=\hat{\imath} \\ 1.6364=v_c-0.2 \omega_{C D E} \\ V_c=1.6364+0.2(-5.25) \\ V_c=0.5864 \mathrm{~m} / \mathrm{s} \rightarrow \\ \end{array} \end{array} $$
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.