Newton’s Second and Third Laws of Motion – PhyLiWriTi 08 and 09

I’ve already posted my limerick about Newton’s First Law of Motion, but here it is again so that I’ve got the complete set here:

Newton’s First Law of Motion

Newton’s law number 1 is the source
For an object not feeling a force
Keeps its speed in a line
Staying still’s also fine
It won’t ever alter its course

And now the next two:

Newton’s Second Law of Motion

Newton’s laws he did once present ‘em,
And now we all just implement ‘em.
Quite clearly one says,
That the sum of forces,
Is the rate of the change of momentum.

That first rhyme is borderline cheating, I think, but the fact that the rhyme is spread over two words overcomes the fact I’ve just repeated ’em at the end. Also it needs a specific pronunciation, but I think that’s relatively normal for poetry.

This is actually a statement of the more general version of Newton’s Second Law of Motion – people are more likely to have seen it as $\latex F = ma$ at school. However I found it easier to make a limerick of so I stuck with this.

Newton’s Third Law of Motion

If a force due to B acts on A:
A similar one you can say,
Due to A acts on B –
The same size you will see,
But driving the opposite way.

I’m really happy with this one. Not only does it describe Newton’s Third Law of Motion really well, but in a way that I hope clarifies one of the things that confuses people some times – the forces don’t just cancel out because they are acting on two different objects.

As always, feel free to suggest a new topic for me to cover!