Distance and Displacement Walkthrough Worksheet What is Distance and Displacement? Imagine the following scenario. A girl walks her dog from her house to the cafe every day. Some days she takes the route along the roads, while on other days, she cuts through the park. 1.2km 1.7km 1.2km It doesn’t matter which route she takes, everyday she ends up at the cafe. The shortest route and most direct path from her house to the cafe is 1.7km southeast. However, if she takes the route along the roads, she travels 2.4km to the cafe. Her final position is always 1.7km from her house, however, her path between the start and finish points is different. This is the difference between distance and displacement. Distance refers to how much ground an object has travelled. Displacement is the difference in position from the initial to the final points irrespective of the path travelled. 1 of 5 Distance and Displacement Walkthrough Worksheet Distance in physics is known as a scalar quantity, while displacement is a vector quantity. Scalar measurements are expressed only as size and no direction - vector measurements include size and direction. Distance is calculated by adding the total length travelled by the object. Displacement can be calculated by examining the difference between the final and initial position of the object. Displacement (change in position) = final position − initial position Example 1: Imagine you are travelling from Town A to Town B. Ordinarily, you would drive the shortest distance to your destination. However, today you come across roadworks and there is an option of a detour. Your journey would now look like this. Town A DETOUR 20km 25km Town B a. What is the distance travelled on your detour route? 25km b. What is your displacement on your detour route? 20km Even though the distance travelled is 25km, the change in position from your initial to your final point remains 20km, irrespective of the detour route. Example 2: A security guard walks the perimeter of a building three times every hour. 4m 3m 3m 4m 2 of 5 Distance and Displacement Walkthrough Worksheet A. What is the distance travelled by the security guard in one hour? The distance can be calculated by adding the length of each of the sides of the building and then multiplying this by the number of times he walks around the building in the hour. B. What is the displacement of the security guard? As the security guard is walking 4m east, then 3m south, then 4m west and finally 3m north, we can say that their overall displacement is 0. This is because the 4m east cancels out the 4m west. Similarly, the 3m south cancels out the 3m north. This results in no change in position overall. 3 of 5 Distance and Displacement Walkthrough Worksheet Motion Questions: Make sure to show all of your working out. 1. Identify the difference between distance and displacement. 2. If you were completing a fitness test such as a beep test, the distance you travel could be 240m but your displacement remains 0. Explain why this would be so. 3. On a weekday, you walk 150m east from home to school and then back home again at the end of the day. a. Calculate the total distance travelled in one school week (Monday-Friday). b. Determine the displacement after walking to school. c. Calculate the displacement once you have arrived home after one school day. 4 of 5 Distance and Displacement Walkthrough Worksheet 4. During a dance routine, you take two steps back, shimmy, then three steps forward, complete two heel-toe touches, another five steps forward, stomp and clap three times and finally four steps back. a. Construct a timeline for your movement during the routine. b. Calculate the distance (in steps) that you travelled during this routine. c. Calculate your displacement (in steps) during the routine. 5 of 5