A car is driven 105 km west and then 30 km southwest. What is the displacement of the car from the point of origin (magnitude and direction)?

User Icon for MathMate MathMate answered
15 years ago

Displacement is a vector. To find the displacement due to multiple legs of a trip, we sum the components (x,y) or (east,north) by resolving each leg into the respective components.

105 km west = (-105,0)
30 km SW = (30cos(225°),30sin(225°))
Sum each component to get the resultant components. The direction can be found with the tan-1(y/x) function.

Post your answer for a check if you wish.

User Icon for KMack KMack answered
14 years ago

7.58

User Icon for joe joe answered
14 years ago

-121.88

User Icon for Explain Bot Explain Bot answered
11 months ago

To find the displacement of the car from the point of origin, we can use vector addition.

First, let's break down the car's movement into two components: west and southwest.

The westward distance of 105 km can be represented as a vector with a magnitude of 105 km in the west direction (left on a map).

The southwest distance of 30 km can be represented as a vector with a magnitude of 30 km in the southwest direction (45 degrees between south and west, in the bottom left direction on a map).

Now, let's add these two vectors to find the resultant displacement of the car:

1. Convert the southwest vector into rectangular or Cartesian coordinates:
The southwest vector can be resolved into two components, one in the west direction and one in the south direction. Since it forms a 45-degree angle with the west direction, both components will have the same magnitude.
The westward component can be calculated using cosine: west_component = magnitude * cos(45)
The southward component can be calculated using sine: south_component = magnitude * sin(45)

In this case, the magnitude is 30 km, so:
west_component = 30 km * cos(45) ≈ 21.2 km
south_component = 30 km * sin(45) ≈ 21.2 km

2. Add the westward distance vector and the west_component vector:
west_displacement = 105 km + west_component ≈ 105 km + 21.2 km = 126.2 km

3. Add the southward distance vector and the south_component vector:
south_displacement = south_component ≈ 21.2 km

4. Combine the west and south displacements using the Pythagorean theorem:
displacement = √(west_displacement^2 + south_displacement^2) = √(126.2 km^2 + 21.2 km^2) ≈ √(17532.68 km^2) ≈ 132.42 km

The displacement of the car from the point of origin is approximately 132.42 km.

To describe the direction, we can use the inverse tangent:
direction = tan^(-1)(south_displacement / west_displacement)
direction = tan^(-1)(21.2 km / 126.2 km) ≈ tan^(-1)(0.168) ≈ 9.19° south of west

Therefore, the magnitude of the displacement is approximately 132.42 km, and the direction is 9.19° south of west.