Math Problem Statement

a truck drives 3 miles north then 4 miles east then 3 miles south then 2 miles northeast, determine the resultant dis placement by drawing a scale diagram by using components

Solution

To determine the truck's resultant displacement, we can break the motion into vector components and then combine them. Here's how to approach this problem step-by-step:

1. Break Down the Motion

The truck moves in four segments:

  1. 3 miles north – A vertical vector pointing upward.
  2. 4 miles east – A horizontal vector pointing to the right.
  3. 3 miles south – A vertical vector pointing downward.
  4. 2 miles northeast – A diagonal vector at a 45-degree angle.

2. Draw the Scale Diagram

To represent the motion graphically:

  • Start at the origin (0, 0).

  • Draw each vector based on the direction and magnitude using a consistent scale (e.g., 1 mile = 1 unit).

  • First, draw a vector 3 units upward for the northward motion.

  • Next, draw a vector 4 units to the right for the eastward motion.

  • Then, draw a vector 3 units downward for the southward motion.

  • Finally, draw a vector of 2 units at a 45-degree angle northeast (which involves breaking it into x and y components).

3. Use Components to Find Resultant

We'll break each vector into x (east-west) and y (north-south) components:

  • 3 miles north:

    • x-component = 0 (no east-west movement)
    • y-component = +3 miles (north)
  • 4 miles east:

    • x-component = +4 miles (east)
    • y-component = 0 (no north-south movement)
  • 3 miles south:

    • x-component = 0 (no east-west movement)
    • y-component = -3 miles (south)
  • 2 miles northeast:

    • Since the vector is at a 45° angle, the components are:
      • x-component = 2cos45=2×22=21.4142 \cos 45^\circ = 2 \times \frac{\sqrt{2}}{2} = \sqrt{2} \approx 1.414 miles
      • y-component = 2sin45=2×22=21.4142 \sin 45^\circ = 2 \times \frac{\sqrt{2}}{2} = \sqrt{2} \approx 1.414 miles

4. Add the Components

  • Total x-component = 0+4+0+1.414=5.4140 + 4 + 0 + 1.414 = 5.414 miles
  • Total y-component = 3+03+1.414=1.4143 + 0 - 3 + 1.414 = 1.414 miles

5. Calculate the Resultant Displacement

Now, we calculate the magnitude of the resultant vector using the Pythagorean theorem:

Resultant Displacement=(5.414)2+(1.414)2\text{Resultant Displacement} = \sqrt{(5.414)^2 + (1.414)^2}

=29.305+1.999= \sqrt{29.305 + 1.999}

=31.3045.6miles= \sqrt{31.304} \approx 5.6 \, \text{miles}

The direction (angle θ) of the resultant vector can be found using:

tanθ=Total y-componentTotal x-component=1.4145.414\tan \theta = \frac{\text{Total y-component}}{\text{Total x-component}} = \frac{1.414}{5.414}

θ=tan1(0.261)14.7north of east\theta = \tan^{-1}(0.261) \approx 14.7^\circ \, \text{north of east}

Result:

The truck's resultant displacement is approximately 5.6 miles at an angle of 14.7° north of east.

Would you like to see more details or a visual representation of the diagram?

Here are 5 related questions to further explore:

  1. What if the truck traveled 5 miles west instead of east?
  2. How would the displacement change if the northeast angle was different?
  3. What are the components of a vector that goes northwest at 3 miles?
  4. How do you calculate resultant displacement for more than four vectors?
  5. What is the difference between distance traveled and displacement?

Tip: Always resolve diagonal vectors into their components for accurate results in vector addition.

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Math Problem Analysis

Mathematical Concepts

Vector Addition
Pythagorean Theorem
Trigonometry
Coordinate Geometry

Formulas

Pythagorean theorem: a^2 + b^2 = c^2
Component form of vectors: Vx = V * cos(θ), Vy = V * sin(θ)
Tangent function for angle: tan(θ) = Vy / Vx

Theorems

Pythagorean Theorem
Basic Trigonometric Functions (Sine, Cosine, Tangent)

Suitable Grade Level

Grades 9-11