Need help with Physics Vectors, not sure how to do them

In summary, the girl's resultant displacement can be found by adding the x and y components of each vector (representing her paths) and using the Pythagorean theorem to find the magnitude and trigonometry to find the angle.
  • #1
2ndperiod
4
0

Homework Statement



A girl delivering newspapers travels 5 blocks west, 8 blocks north, then 6 blocks east. What is the magnitude of her resultant displacement? Answer in unit of blocks.


Homework Equations



Is there an equation for this? I don't think so?

The Attempt at a Solution



My attempt is I drew a graph and went 5 to the left, 8 up, and 6 to the right. from there what should I do? Or is that incorrect?

THANKS SO MUCH
 
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  • #2
That is the correct approach. The resulting displacement is just the sum of those individual vectors. If you drew them to scale, you can connect the starting point to the ending point and measure that vector to get your answer.
 
  • #3
AEM said:
That is the correct approach. The resulting displacement is just the sum of those individual vectors. If you drew them to scale, you can connect the starting point to the ending point and measure that vector to get your answer.

And if I didnt draw to scale, how could I find it? THanks!
 
  • #4
2ndperiod said:

Homework Statement



A girl delivering newspapers travels 5 blocks west, 8 blocks north, then 6 blocks east. What is the magnitude of her resultant displacement? Answer in unit of blocks.


Homework Equations



Is there an equation for this? I don't think so?

The Attempt at a Solution



My attempt is I drew a graph and went 5 to the left, 8 up, and 6 to the right. from there what should I do? Or is that incorrect?

THANKS SO MUCH

Here's how it works in detail: Each path that the girls takes can be represented by a vector. When drawn out in an x-y coordinate system you can express each vector in terms of its x and y components. The resultant vector is found by adding up all of the x components and then adding up all the y components. You have to be careful to include the signs of the components because those going in the positive direction are plus (naturally) while those going in the negative direction are minus. For your problem you can take north as the positive y direction then south is the negative y direction. You want to take east as the positive x direction and west as the negative x direction. So walking 5 blocks west is -5 in the x direction, while walking 6 blocks east is +6 in the x direction. Add these up and you see she has walked a net 1 in the x direction. Now, I ask you: What is the amount she walked in the y direction?

You now have enough information to determine the components of her resultant displacement. Using the Pythagorean theorem you can find the length of the resultant vector (her displacement) and with a little trigonometry you can find the angle that vector makes with the x axis.
 
  • #5


Hi there,

It looks like you're on the right track! Drawing a graph is a great way to visualize the problem and understand what's going on. To find the magnitude of the resultant displacement, you can use the Pythagorean theorem. This states that the magnitude of the resultant displacement (R) is equal to the square root of the sum of the squares of the individual displacements (x and y). So in this case, R = √(5²+8²+6²) = √125 = 11.18 blocks.

Hope this helps! Let me know if you have any other questions. Good luck with your physics vectors!
 

FAQ: Need help with Physics Vectors, not sure how to do them

What are vectors in physics?

Vectors in physics are quantities that have both magnitude and direction. They are used to represent physical quantities such as velocity, force, and displacement.

How do you add or subtract vectors?

To add or subtract vectors, you must first break them down into their horizontal and vertical components. Then, you can use the Pythagorean theorem and trigonometric functions to calculate the resultant vector.

What is the difference between scalar and vector quantities?

Scalar quantities only have magnitude, while vector quantities have both magnitude and direction. Examples of scalar quantities include temperature and mass, while examples of vector quantities include velocity and acceleration.

Can you give an example of a real-life application of vectors?

Vectors are used in many real-life applications, such as navigation and aviation. For example, a pilot must use vectors to determine the correct heading and speed to reach their destination.

What is the importance of understanding vectors in physics?

Understanding vectors in physics is crucial because they are used to describe the motion and forces of objects in the physical world. Without a solid understanding of vectors, it would be challenging to accurately analyze and predict the behavior of physical systems.

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