Head First Physics

Chapter 19. Oscillations (Part 1): Round and round

Things can look very different when you see them from another angle. So far you’ve been looking at circular motion from above - but what does it look like from the side? In this chapter, you’ll tie together your circular motion and trigonometry superpowers as you learn extended definitions of sine and cosine. Once you’re done, you’ll be able to deal with anything that’s moving around a circle - whichever way you look at it.

Welcome to the fair!

After your success at hamster training, you’ve got another client who needs your help. Jane’s opening up a new booth at the local fair, and wants to build a duck-shooting competition - with a twist.

Note

This chapter builds on what we did in Chapter 16, with the hamster trainer.

At the moment, she’s got a duck moving around in a circle. But she expects the game to be popular, and the rotating duck takes up space that she could use to pack in more paying customers.

So instead, Jane wants to let players shoot at a digital version of the duck, displayed on a giant flat screen. Each player feels like they’re shooting at a real rotating duck, but Jane can just monitor the screen to run the game.

Jane’s got all the equipment: a duck mounted on a rotating stick, a screen, and light guns that can shoot at the screen. The screen even registers where the gun hits, and which player shot the duck. Your job is ...