Processing Math: Done
Solution 8.4a
From Mechanics
(Difference between revisions)
(New page: Here we have <math>\mathbf{a}=0.2\mathbf{i}+0.3\mathbf{j},\ \</math> <math>\mathbf{u}=4\mathbf{i}– 8\mathbf{j}\ \</math> and <math>{\mathbf{ r}}_{0}=6\mathbf{i}+2\mathbf{j}</math>.) |
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- | Here we have <math>\mathbf{a}=0.2\mathbf{i}+0.3\mathbf{j},\ \</math> <math>\mathbf{u}=4\mathbf{i}– 8\mathbf{j}\ \</math> and <math> | + | Here we have <math>\mathbf{a}=0\textrm{.}2\mathbf{i}+0\textrm{.}3\mathbf{j},\ \</math> <math>\mathbf{u}=4\mathbf{i}– 8\mathbf{j}\ \</math> and <math>\ \ \mathbf{ r}_{0}=6\mathbf{i}+2\mathbf{j}</math>. |
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+ | Using <math>\mathbf{v}=\mathbf{u}+\mathbf{a}t\ \</math> at <math>\ \ t=10</math> gives | ||
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+ | <math>\mathbf{v}=4\mathbf{i}– 8\mathbf{j}+(0\textrm{.}2\mathbf{i}+0\textrm{.}3\mathbf{j})\times 10\ \</math> or | ||
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+ | <math>\mathbf{v}=6\mathbf{i}– 5\mathbf{j}\ \ \text{m}{{\text{s}}^{-1}}</math> | ||
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+ | The speed is the magnitude of this velocity vector. | ||
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+ | <math>v=\sqrt{{{6}^{2}}+{{\left( -5 \right)}^{2}}}=\sqrt{61}=7\textrm{.}81\ \text{m}{{\text{s}}^{-1}}</math> |
Current revision
Here we have
Using
10
The speed is the magnitude of this velocity vector.
62+
−5
2=
61=7.81 ms−1