4.5.6.1.2 Speed

# 4.5.6.1.2 Speed

## Content

Speed does not involve direction. Speed is a scalar quantity.

The speed of a moving object is rarely constant. When people walk, run or travel in a car their speed is constantly changing.

The speed at which a person can walk, run or cycle depends on many factors including: age, terrain, fitness and distance travelled.

Content

Key opportunities for skills development

Typical values may be taken as: walking ̴ 1.5 m/s

running ̴ 3 m/s

cycling ̴ 6 m/s.

Students should be able to recall typical values of speed for a person walking, running and cycling as well as the typical values of speed for different types of transportation systems.

It is not only moving objects that have varying speed. The speed of sound and the speed of the wind also vary.

A typical value for the speed of sound in air is 330 m/s.

Students should be able to make measurements of distance and time and then calculate speeds of objects.

For an object moving at constant speed the distance travelled in a specific time can be calculated using the equation:

distance travelled = speed × time

s =vt

distance, s, in metres, m

speed, v, in metres per second, m/s

time, t, in seconds, s

Students should be able to calculate average speed for non-uniform

motion.

MS 1a Recognise and use expressions in decimal form

MS 3c Substitute numerical values into algebraic equations using appropriate units for physical quantities

MS 1f Understand the terms mean, mode and median

MS 3b Change the subject of an equation

MS 3c Substitute numerical values into algebraic equations using appropriate units for physical quantities

Resources

Video

Practicals

Demo:

### Safety

Asthma attack risk for selected student?