Idea 8of 8Builds onDraw every forceA perfect draw
The net arrow
Thirty newtons push right, fifteen drag left. What remains?
Today you'll discover
- what the arrows add up to
- why the leftover is the one that matters
- a crate that moves with nothing left over
Think first30 N push right, 15 N drag left
30 N to the right, 15 N to the left. What is the total?
Decide first, then press Next. Watch the heavier arrow appear beside the crate.
A box on a floor with four arrows from its centre: down, up, a long one to the right and a shorter one to the left. After a prediction, a heavier arrow appears beside the box pointing right, shorter than the push. The last step shortens the push to match the drag and asks for the net force.
See the whole ideathe big idea and the key word, in one place
The big idea
The net force is every force added, directions included.
Easy to get wrongZero net force means no change, not no motion. A crate sliding at a steady speed has a net force of zero, just like a book at rest.
Key word
- net force
- the vector sum of all the forces on one object; the only thing that changes its motion
About this modelArrows are forces, not motion: a box can move with no arrow pointing its way.
Arrows are forces, not motion: a box can move with no arrow pointing its way.
Ready to use it?
- Add the forces on a described object and give the net force with its direction.