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A car travels 10 km southeast and then 15 km in a direction 60° north of east. Find the direction of the car's resultant vector.

User Pablo Viacheslav
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1 Answer

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28 votes

ANSWER

85.9° North of East

Step-by-step explanation

First, we have to make a sketch:

We have to find the resultant vector of the car's displacement.

The horizontal component of the displacement of the car:


\begin{gathered} d_x=-10\cos 45+15\cos 60 \\ d_x=(-10\cdot0.7071)+(15\cdot0.5)=-7.071+7.5 \\ d_x=0.429\operatorname{km} \end{gathered}

The vertical component of the displacement of the car is:


\begin{gathered} d_y=-10\sin 45+15\sin 60 \\ d_y=(-10\cdot0.7071)+_{}(15\cdot0.8660)=-7.071+12.990 \\ d_y=5.919\operatorname{km} \end{gathered}

To find the direction of the car's resultant vector, apply the formula:


\theta=\tan ^(-1)((d_y)/(d_x))

Therefore, we have:


\begin{gathered} \theta=\tan ^(-1)((5.919)/(0.429)) \\ \theta=\tan ^(-1)(13.7972) \\ \theta=85.9\degree \end{gathered}

Hence, the car's resultant vector is 85.9° North of East.

A car travels 10 km southeast and then 15 km in a direction 60° north of east. Find-example-1
User Daniel Myers
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2.8k points