2D Motion & Vectors

What's better than motion in 1 dimension? Motion in 2 dimensions! Two-dimensional (2D) motion is when an object moves in two directions (along two axes) at the same time. That could be an object that moves horizontally and vertically at the same time, like a cannon ball launched through the air. Or that could be an object that moves in two horizontal directions at the same time, like a car driving North and East at the same time (Northeast).

In this lesson we'll learn about 2D motion on a horizontal plane and things that move along the ground in two dimensions. Think of a car driving around, a boat crossing a river, or someone skating around on a frozen pond. In the next lesson we'll learn about 2D projectile motion.

We're going to describe 2D motion using vectors, which means we can use the trig functions to break down 2D motion into its 1D components: motion in the x direction and motion in the y direction. These two motions are completely independent - they don't affect each other. However, they are happening at the same time, so we can use time as the link between our x motion and y motion equations.

We'll learn how to describe position, displacement and velocity in two dimensions, as well as how to add vectors using the tip-to-tail method or by adding components.

2D Position, Coordinates & Displacement Vectors (27:29)
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Introduction to 2D motion

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2D position and coordinates

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2D displacement and vectors

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How to describe vector angles

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How to Add Vectors (23:28)
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Example 1 - Adding 1D vectors

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Example 2 - Adding 2D vectors

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Example 3 - Adding 2D vectors with negative components

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Adding vectors graphically with the tip-to-tail method

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Velocity Vectors in 2D Motion (30:15)
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Video setup: constant velocity with no friction

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Velocity vectors

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2D velocity vectors and components

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Adding velocity vectors, finding the magnitude and angle

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x and y motions are independent

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Example: boat crossing a river

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From the Vectors study guide:

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2D Motion & Vectors Example Problems & Tips (32:26)
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Key concepts and tips for solving 2D motion and vector problems

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Problem 1: Adding 2D vectors

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Problem 2: Displacement vectors

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Problem 3: Velocity vectors

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Problem 4: Coordinates, displacement and velocity vectors, kinematics

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Multiple-Choice Questions

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Introduction

What's better than motion in 1 dimension? Motion in 2 dimensions! Two-dimensional (2D) motion is when an object moves in two directions (along two axes) at the same time. That could be an object that moves horizontally and vertically at the same time, like a cannon ball launched through the air. Or that could be an object that moves in two horizontal directions at the same time, like a car driving North and East at the same time (Northeast).

In this lesson we'll learn about 2D motion on a horizontal plane and things that move along the ground in two dimensions. Think of a car driving around, a boat crossing a river, or someone skating around on a frozen pond. In the next lesson we'll learn about 2D projectile motion.

We're going to describe 2D motion using vectors, which means we can use the trig functions to break down 2D motion into its 1D components: motion in the x direction and motion in the y direction. These two motions are completely independent - they don't affect each other. However, they are happening at the same time, so we can use time as the link between our x motion and y motion equations.

We'll learn how to describe position, displacement and velocity in two dimensions, as well as how to add vectors using the tip-to-tail method or by adding components.

Study Guide

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