Introduction to Distance and Displacement

Distance, Displacement, & S/D/T

by Erin Hannan

​What we will learn about...

• ​student outcomes for physics

• ​distance vs displacement

• ​calculating distance and displacement

• ​relationship between speed, distance, and time

​Student Outcomes

​ 

1. Contrast distance and displacement

2. Calculate distance of an object

3. Calculate displacement of an object

4. Describe (and therefore calculate from) the relationship between speed, distance and time

5. Contrast between speed and velocity

6. Explain the difference between and calculate instant and average speed

7. Interpret and construct distance/displacement and time graphs

8. Explain the concept of acceleration and deceleration

9. Extension: calculate acceleration of an object

10. Describe a force as a push, pull or twist to change the shape or acceleration of an object

11. Recall that force is measured in Newtons (N)

12. Recall and explain Newton’s Laws of Motion

13. Explain the concept of inertia

14. Calculate using Newton’s 2nd Law (f = ma)

15. Demonstrate your understanding of forces in the ‘real world’ (e.g. a car accident etc.)

Multiple Choice

David walks 3 km north, and then turns east and walks 4 km. What is the distance?

• 7 km

• 3 km

• 4 km

• 1 km

Multiple Choice

Bill runs 400 meters to Andy's house, turns around, and runs 400 meters back home.  What is Bill's displacement?

• 0 meters

• 400 meters

• 800 meters

• 1600 meters

​Distance vs Displacement

• ​distance = scalar quantity

  • ​how much ground has been covered during motion by an object

• ​displacement = vector quantity

  • ​how far from its original position an object is during motion

• ​Remember! Vector quantities have both a magnitude and a direction

​Example question:

• ​The boy on the bike rides from point A to point C, via point B. What is his distance and displacement?

Multiple Choice

Displacement is distance combined with

• direction

• speed

• velocity

• magnitude

​Speed, distance, time

• ​speed is a scalar quantity, it only has a magnitude

• ​we can calculate average speed, distance travelled, or time taken to travel by rearranging 1 formula

• ​you sometimes seen speed represented as 'v' for velocity - we will learn more about velocity next week!

​Example question:

• ​An Olympic runner travels 100m in 9.58 seconds. What is their average speed in m/s?

​Example question:

• ​Whilst driving to work in the morning Miss Hannan travels 14 km. The drive took 30 minutes. What was her average speed in m/s?

​Example question:

• ​A biker's average speed is 25km/h. They travelled 150km, how long did it take them?

Multiple Choice

Because displacement has a magnitude and direction it is called a ______. 

• distance

• vector

• arrow

• length

Multiple Choice

From the figure, what is the displacement?

• 20 meters

• 25 meters

• 15 meters

• 25 meters NE

Multiple Choice

What is the equation to calculate speed?

• speed = distance/time

• speed = time/distance

• speed = time x distance 

• speed = speed/time 

Multiple Choice

A train travels 25 km in .5 hrs. How fast is the train going?

• 25 miles/hr

• 5 miles/hr

• 125 km/hr

• 50 km/hr

Multiple Choice

How far will a person go if they jog for 2 hours at a speed of 12 km/hr?

• 6 km

• 0.5 km

• 10 km

• 24 km