Idea 1of 6Builds onWhich wayStart to finish
Two arrows, one path
North, then east. How far from the start?
Today you'll discover
- why two legs at a corner are less than their sum
- the one arrow that replaces both
- where its tail and its head sit
Think firstA hiker walks north, then turns and walks east
She walks ten kilometres north, then fifteen east. How far is she from the start?
Decide first, then press Next. Watch where the second arrow starts and where the one arrow runs.
A compass rose in the corner, north up. After a prediction, an arrow of ten kilometres runs north from a start flag; a second arrow of fifteen kilometres runs east from its head; then one arrow runs straight from the start flag to the second arrow's head and is named. The last step shows a six-leg walk round town blocks and asks for the one arrow from start to finish.
See the whole ideathe big idea and the key word, in one place
The big idea
Tail to head. The resultant runs first tail to last head.
Compare themAlong one line, legs add as signed numbers: six east and four west is two east. At a corner they add tail to head, and the one arrow that results is shorter than the two sizes added.
Key word
- resultant
- the single vector that replaces several added tail to head; it runs from the first tail to the last head
About this modelArrows are drawn to the scale in the corner; a bearing turns from north (or east).
Arrows are drawn to the scale in the corner; a bearing turns from north (or east).
Ready to use it?
- Draw two legs tail to head and say where the resultant runs.