Now the flippers pass their surface speed. A point on a turning bar moves at speed × distance from the pivot, at
right angles to the bar, so the tip moves fastest: hit the ball with the tip to send it far.
```js
// A point on a turning flipper moves at speed × distance from the pivot, at right angles to it.
hitSegment(f.x, f.y, t.x, t.y, 0.3, (px, py) => ({ x: -f.speed * (py - f.y), y: f.speed * (px - f.x) }))
```
What it means
(px - f.x, py - f.y) is the arrow from the pivot to the point. Turning it a quarter turn gives
(-(py - f.y), px - f.x): the direction the point moves. Multiplying by f.speed gives its speed.
The farther from the pivot, the longer the arrow, the faster the point.
Your turn
In step, replace the flipper's hitSegment(...) line with the comment and the new line.