Displacement Calculation: Need Help Solving Vector Problem

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Homework Help Overview

The discussion revolves around a vector problem involving the displacement of a car that travels 150 km west and then 30 km southwest. Participants are exploring how to calculate the resultant displacement in terms of both magnitude and direction.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss breaking down the vectors into components and adding them. There is uncertainty about how to calculate the components of the second vector, particularly regarding the angle and magnitude. Questions arise about the use of trigonometric functions to find the components and how to apply them in the context of the problem.

Discussion Status

The discussion is ongoing, with participants providing guidance on how to approach the problem. Some have suggested methods for breaking down the vectors, while others express confusion about specific calculations and the use of angles. There is no explicit consensus yet, but various interpretations and approaches are being explored.

Contextual Notes

Participants are grappling with the definitions of vector components and the implications of the angle used for the southwest direction. There is a noted lack of clarity regarding the initial conditions and the values needed for calculations.

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vector problem..PLEASE HELP!

A car is driven 150 km west and then 30 km southwest. What is the displacement of the car from the point of origin (magnitude and direction)?

i have no clue how to start..could someone help me?
 
Last edited:
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Break down the vectors into components and then add up the components to get the sum of the two vectors.
 
Right, and I would assume southwest to mean to have a reference angle of 45 degrees.
 
i know that V1x = -150 and V1y = 0. but I'm confused how to find V2x and V2y. do i use the Vx=V1x + V2x? but i don't know what Vx is. and i know that to find Vx you use Vx=Vcos(angle) but i don't have V either.

where do i go from here?
 
Last edited:
someone help please! i don't know where to go from here! (see above message)
 
[itex]\vec{v_1} = 150km \ west[/itex]

[itex]\vec{v_2} = 30km \ southwest[/itex]

Vector 1 is purely East West so it has no north south component.
Vector 2 has components in both north south and east west. SW is 45 degrees south of west. Break it up into its components.
 
You're complicating things.

First of all, V(x) = V(x1) + V(x2) and V(y) = V(y1) + V(y2), right? It appears you know this already.

You've solved for V(x1) and V(y1). For V(x2) and V(y2), you must use your formulas. That is, V(y2) = V times the sine of the angle and V(x2) = V times the cosine of the angle. The angle is 45 and the magnitude is 30. Just plug in the values and get the x and y components of the second vector. Then plug these results into the formula displayed at the top of this post and you have the x and y components of the final vector. Using Pythagoras' Theorem and basic trigonometry, you can then find the magnitude and direction of the final vector. Do you understand?
 

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