Common Core: High School - Number and Quantity : Compute Magnitude and Direction of a Scalar Multiple: CCSS.Math.Content.HSN-VM.B.5b

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All Common Core: High School - Number and Quantity Resources

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Example Questions

Example Question #1 : Compute Magnitude And Direction Of A Scalar Multiple: Ccss.Math.Content.Hsn Vm.B.5b

Calculate \displaystyle \left \| -3v\right \|, where \displaystyle v=< 0,2>. Also determine the direction of the resulting vector.

Possible Answers:

\displaystyle \left \| -3\:v\right \|=6, Direction is the same as \displaystyle v.

\displaystyle \left \| -3\:v\right \|=6, Direction is away from \displaystyle v.

\displaystyle \left \| -3\:v\right \|=-6, Direction is away from \displaystyle v.

\displaystyle \left \| -3\:v\right \|=3, Direction is the same as \displaystyle v.

\displaystyle \left \| -3\:v\right \|=-3, Direction is away from \displaystyle v.

Correct answer:

\displaystyle \left \| -3\:v\right \|=6, Direction is away from \displaystyle v.

Explanation:

In order to solve the first part of the problem, we need to remember how to take the magnitude of a vector and scalar.

\displaystyle \left \| c\:v\right \|=\left | c\right |\:\left \| v\right \|, where \displaystyle c is a scalar.

Now lets calculate this.

\displaystyle \left \| -3\:v\right \|=\left | -3\right |\left \| v\right \|

\displaystyle =3\cdot\sqrt{0^2+2^2}=3\cdot\sqrt{0+4}=3\sqrt{4}=3\cdot2=6

As for the direction of the vector, since \displaystyle c< 0, the resulting vector will be against the original vector \displaystyle v.

See below for a picture.

Vecscale

Example Question #2 : Compute Magnitude And Direction Of A Scalar Multiple: Ccss.Math.Content.Hsn Vm.B.5b

Calculate \displaystyle \left \| 1v\right \|, where \displaystyle v=< -2,-4>. Also determine the direction of the resulting vector.

Possible Answers:

\displaystyle \left \| 1\:v\right \|=2, Direction is the same as \displaystyle v.

\displaystyle \left \| 1\:v\right \|=2\sqrt{5}, Direction is the same as \displaystyle v.

 





\displaystyle \left \| 1\:v\right \|=-2\sqrt{5}, Direction is away from \displaystyle v.

\displaystyle \left \| 1\:v\right \|=2\sqrt{5}, Direction is away from \displaystyle v.

\displaystyle \left \| 1\:v\right \|=\sqrt{5}, Direction is the same as \displaystyle v.

Correct answer:

\displaystyle \left \| 1\:v\right \|=2\sqrt{5}, Direction is the same as \displaystyle v.

 





Explanation:

In order to solve the first part of the problem, we need to remember how to take the magnitude of a vector and scalar.

\displaystyle \left \| c\:v\right \|=\left | c\right |\:\left \| v\right \|, where \displaystyle c is a scalar.

Now lets calculate this.

\displaystyle \left \| 1\:v\right \|=\left | 1\right |\left \| v\right \|

\displaystyle =1\cdot\sqrt{(-2)^2+(-4)^2}=1\cdot\sqrt{4+16}=1\sqrt{20}=2\sqrt{5}

As for the direction of the vector, since \displaystyle c>0, the resulting vector will be in the same direction as the original vector \displaystyle v

.Screen shot 2016 03 07 at 10.10.02 am

Example Question #3 : Compute Magnitude And Direction Of A Scalar Multiple: Ccss.Math.Content.Hsn Vm.B.5b

Calculate \displaystyle \left \| 2v\right \|, where \displaystyle v=< 1,2>. Also determine the direction of the resulting vector.

Possible Answers:

\displaystyle \left \| 2\:v\right \|=\sqrt{5}, Direction is the same as \displaystyle v.

\displaystyle \left \| 2\:v\right \|=2\sqrt{5}, Direction is the same as \displaystyle v

\displaystyle \left \| 2\:v\right \|=4\sqrt{5}, Direction is away from \displaystyle v.

\displaystyle \left \| 2\:v\right \|=2\sqrt{5}, Direction is away from \displaystyle v.

\displaystyle \left \| 2\:v\right \|=2, Direction is the same as \displaystyle v.

Correct answer:

\displaystyle \left \| 2\:v\right \|=2\sqrt{5}, Direction is the same as \displaystyle v

Explanation:

In order to solve the first part of the problem, we need to remember how to take the magnitude of a vector and scalar.

\displaystyle \left \| c\:v\right \|=\left | c\right |\:\left \| v\right \|, where \displaystyle c is a scalar.

Now lets calculate this.

\displaystyle \left \| 2\:v\right \|=\left | 2\right |\left \| v\right \|

\displaystyle =2\cdot\sqrt{1^2+2^2}=2\cdot\sqrt{1+4}=2\sqrt{5}

As for the direction of the vector, since \displaystyle c>0, the resulting vector will be in the same direction as the original vector \displaystyle v.

See below for a picture.

 


Screen shot 2016 03 07 at 10.16.42 am

Example Question #4 : Compute Magnitude And Direction Of A Scalar Multiple: Ccss.Math.Content.Hsn Vm.B.5b

Calculate \displaystyle \left \| -4v\right \|, where \displaystyle v=< -3,-1>. Also determine the direction of the resulting vector.

Possible Answers:

\displaystyle \left \| -4\:v\right \|=4\sqrt{10}, Direction is the same as \displaystyle v.

\displaystyle \left \| -4\:v\right \|=4\sqrt{10}, Direction is away from \displaystyle v.

\displaystyle \left \| -4\:v\right \|=-4, Direction is the same as \displaystyle v.

\displaystyle \left \| -4\:v\right \|=-4, Direction is away from \displaystyle v.

\displaystyle \left \| -4\:v\right \|=-4\sqrt{10}, Direction is away from \displaystyle v.

Correct answer:

\displaystyle \left \| -4\:v\right \|=4\sqrt{10}, Direction is away from \displaystyle v.

Explanation:

In order to solve the first part of the problem, we need to remember how to take the magnitude of a vector and scalar.

\displaystyle \left \| c\:v\right \|=\left | c\right |\:\left \| v\right \|, where \displaystyle c is a scalar.

Now lets calculate this.

\displaystyle \left \| -4\:v\right \|=\left | -4\right |\left \| v\right \|

\displaystyle =4\cdot\sqrt{(-3)^2+(-1)^2}=4\cdot\sqrt{9+1}=4\sqrt{10}

As for the direction of the vector, since \displaystyle c< 0, the resulting vector will be against the original vector \displaystyle v.

See below for a picture.


Screen shot 2016 03 07 at 10.20.27 am

Example Question #5 : Compute Magnitude And Direction Of A Scalar Multiple: Ccss.Math.Content.Hsn Vm.B.5b

Calculate \displaystyle \left \| -9v\right \|, where \displaystyle v=< 1,4>. Also determine the direction of the resulting vector.

Possible Answers:

\displaystyle \left \| -9\:v\right \|=-9\sqrt{17}, Direction is away from \displaystyle v.

\displaystyle \left \| -9\:v\right \|=\sqrt{17}, Direction is the same as \displaystyle v.

\displaystyle \left \| -9\:v\right \|=9, Direction is away from \displaystyle v.

\displaystyle \left \| -9\:v\right \|=9\sqrt{17}, Direction is away from \displaystyle v.




 

\displaystyle \left \| -9\:v\right \|=9\sqrt{17}, Direction is the same as \displaystyle v.

Correct answer:

\displaystyle \left \| -9\:v\right \|=9\sqrt{17}, Direction is away from \displaystyle v.




 

Explanation:

In order to solve the first part of the problem, we need to remember how to take the magnitude of a vector and scalar.

\displaystyle \left \| c\:v\right \|=\left | c\right |\:\left \| v\right \|, where \displaystyle c is a scalar.

Now lets calculate this.

\displaystyle \left \| -9\:v\right \|=\left | -9\right |\left \| v\right \|

\displaystyle =9\cdot\sqrt{1^2+4^2}=9\cdot\sqrt{1+16}=9\sqrt{17}

As for the direction of the vector, since \displaystyle c< 0, the resulting vector will be against the original vector \displaystyle v.

See below for a picture.


Screen shot 2016 03 07 at 10.32.32 am

Example Question #6 : Compute Magnitude And Direction Of A Scalar Multiple: Ccss.Math.Content.Hsn Vm.B.5b

Calculate \displaystyle \left \| -2v\right \|, where \displaystyle v=< 4,10>. Also determine the direction of the resulting vector.

Possible Answers:


\displaystyle \left \| -2\:v\right \|=-2\sqrt{29}, Direction is away from \displaystyle v.

\displaystyle \left \| -2\:v\right \|=4\sqrt{29}, Direction is away from \displaystyle v.




\displaystyle \left \| -2\:v\right \|=-4\sqrt{29}, Direction is away from \displaystyle v.

\displaystyle \left \| -2\:v\right \|=4\sqrt{29}, Direction is the same as \displaystyle v.

\displaystyle \left \| -2\:v\right \|=2\sqrt{29}, Direction is the same as \displaystyle v.

Correct answer:

\displaystyle \left \| -2\:v\right \|=4\sqrt{29}, Direction is away from \displaystyle v.




Explanation:

In order to solve the first part of the problem, we need to remember how to take the magnitude of a vector and scalar.

\displaystyle \left \| c\:v\right \|=\left | c\right |\:\left \| v\right \|, where \displaystyle c is a scalar.

Now lets calculate this.

\displaystyle \left \| -2\:v\right \|=\left | -2\right |\left \| v\right \|

\displaystyle =2\cdot\sqrt{4^2+10^2}=2\cdot\sqrt{16+100}=2\sqrt{116}=4\sqrt{29}

As for the direction of the vector, since \displaystyle c< 0, the resulting vector will be against the original vector \displaystyle v.

See below for a picture.

Screen shot 2016 03 07 at 10.42.39 am

Example Question #7 : Compute Magnitude And Direction Of A Scalar Multiple: Ccss.Math.Content.Hsn Vm.B.5b

Calculate \displaystyle \left \| 10v\right \|, where \displaystyle v=< 2,-1>. Also determine the direction of the resulting vector.

Possible Answers:

\displaystyle \left \| 5\:v\right \|=-5\sqrt{5}, Direction is away from \displaystyle v.

\displaystyle \left \| 10\:v\right \|=5\sqrt{5}, Direction is the same as \displaystyle v.

\displaystyle \left \| 10\:v\right \|=10\sqrt{5}, Direction is the same as \displaystyle v.

\displaystyle \left \| 10\:v\right \|=10\sqrt{5}, Direction is away from \displaystyle v.





\displaystyle \left \| 10\:v\right \|=-10\sqrt{5}, Direction is away from \displaystyle v.

Correct answer:

\displaystyle \left \| 10\:v\right \|=10\sqrt{5}, Direction is the same as \displaystyle v.

Explanation:

In order to solve the first part of the problem, we need to remember how to take the magnitude of a vector and scalar.

\displaystyle \left \| c\:v\right \|=\left | c\right |\:\left \| v\right \|, where \displaystyle c is a scalar.

Now lets calculate this.

\displaystyle \left \| 10\:v\right \|=\left | 10\right |\left \| v\right \|

\displaystyle =10\cdot\sqrt{2^2+(-1)^2}=10\cdot\sqrt{4+1}=10\sqrt{5}

As for the direction of the vector, since \displaystyle c>0, the resulting vector in the same direction as the original vector \displaystyle v.

See below for a picture.

 

Screen shot 2016 03 07 at 10.54.13 am

Example Question #8 : Compute Magnitude And Direction Of A Scalar Multiple: Ccss.Math.Content.Hsn Vm.B.5b

Calculate \displaystyle \left \| 13v\right \|, where \displaystyle v=< 0,-6>. Also determine the direction of the resulting vector.

Possible Answers:

\displaystyle \left \| 13\:v\right \|=-78, Direction is away from \displaystyle v.

\displaystyle \left \| 13\:v\right \|=13, Direction is the same as \displaystyle v.

\displaystyle \left \| 13\:v\right \|=78, Direction is the same as \displaystyle v.

\displaystyle \left \| 13\:v\right \|=-13, Direction is away from \displaystyle v.

\displaystyle \left \| 13\:v\right \|=78, Direction is away from \displaystyle v.

 




Correct answer:

\displaystyle \left \| 13\:v\right \|=78, Direction is the same as \displaystyle v.

Explanation:

In order to solve the first part of the problem, we need to remember how to take the magnitude of a vector and scalar.

\displaystyle \left \| c\:v\right \|=\left | c\right |\:\left \| v\right \|, where \displaystyle c is a scalar.

Now lets calculate this.

\displaystyle \left \| 13\:v\right \|=\left | 13\right |\left \| v\right \|

\displaystyle =13\cdot\sqrt{0^2+6^2}=13\cdot\sqrt{0+36}=13\sqrt{36}=13\cdot6=78

As for the direction of the vector, since \displaystyle c>0, the resulting vector will be in the same direction as the original vector \displaystyle v.

See below for a picture.


Screen shot 2016 03 07 at 11.09.17 am

Example Question #1 : Compute Magnitude And Direction Of A Scalar Multiple: Ccss.Math.Content.Hsn Vm.B.5b

Calculate \displaystyle \left \| 11v\right \|, where \displaystyle v=< 5,-1>. Also determine the direction of the resulting vector.

Possible Answers:

\displaystyle \left \| 11\:v\right \|=11\sqrt{26}, Direction is the same as \displaystyle v.

\displaystyle \left \| 11\:v\right \|=11\sqrt{26}, Direction is away from \displaystyle v.



\displaystyle \left \| 11\:v\right \|=-11\sqrt{26}, Direction is away from \displaystyle v.

\displaystyle \left \| 11\:v\right \|=\sqrt{26}, Direction is the same as \displaystyle v.



\displaystyle \left \| 11\:v\right \|=-\sqrt{26}, Direction is away from \displaystyle v.

Correct answer:

\displaystyle \left \| 11\:v\right \|=11\sqrt{26}, Direction is the same as \displaystyle v.

Explanation:

In order to solve the first part of the problem, we need to remember how to take the magnitude of a vector and scalar.

\displaystyle \left \| c\:v\right \|=\left | c\right |\:\left \| v\right \|, where \displaystyle c is a scalar.

Now lets calculate this.

\displaystyle \left \| 11\:v\right \|=\left | 11\right |\left \| v\right \|

\displaystyle =11\cdot\sqrt{5^2+(-1)^2}=11\cdot\sqrt{25+1}=11\sqrt{26}

As for the direction of the vector, since \displaystyle c>0, the resulting vector will be in the same direction as the original vector \displaystyle v.

See below for a picture.

Screen shot 2016 03 07 at 11.45.20 am

Example Question #2 : Compute Magnitude And Direction Of A Scalar Multiple: Ccss.Math.Content.Hsn Vm.B.5b

Calculate \displaystyle \left \| -12v\right \|, where \displaystyle v=< 4,4>. Also determine the direction of the resulting vector.

Possible Answers:

\displaystyle \left \| -12\:v\right \|=-\sqrt{2}, Direction is away from \displaystyle v.

\displaystyle \left \| -12\:v\right \|=48\sqrt{2}, Direction is away from \displaystyle v.





\displaystyle \left \| -12\:v\right \|=48\sqrt{2}, Direction is the same as \displaystyle v.

\displaystyle \left \| -12\:v\right \|=-48\sqrt{2}, Direction is away from \displaystyle v.

\displaystyle \left \| -12\:v\right \|=\sqrt{2}, Direction is the same as \displaystyle v.

Correct answer:

\displaystyle \left \| -12\:v\right \|=48\sqrt{2}, Direction is away from \displaystyle v.





Explanation:

In order to solve the first part of the problem, we need to remember how to take the magnitude of a vector and scalar.

\displaystyle \left \| c\:v\right \|=\left | c\right |\:\left \| v\right \|, where \displaystyle c is a scalar.

Now lets calculate this.

\displaystyle \left \| -12\:v\right \|=\left | -12\right |\left \| v\right \|

\displaystyle =12\cdot\sqrt{4^2+4^2}=12\cdot\sqrt{16+16}=12\sqrt{32}=48\sqrt{2}

As for the direction of the vector, since \displaystyle c< 0, the resulting vector will be against the original vector \displaystyle v.

See below for a picture.


Screen shot 2016 03 07 at 11.53.48 am

All Common Core: High School - Number and Quantity Resources

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