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docs/reference/js/lessons/glowing-pendulum/challenges.md

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+# glowing pendulum challenges
+
+Coding challenges for the glowing pendulum tutorial. #docs
+
+## Before we get started
+
+Complete the following guided tutorial:
+
+* [tutorial](/microbit/lessons/glowing-pendulum/tutorial)
+
+At the end of the tutorial, click `keep editing`. Your code should look like this:
+
+```
+basic.forever(() => {
+    let acceleration = input.acceleration("y")
+    acceleration = math.abs(acceleration)
+    acceleration = acceleration / 4
+    led.setBrightness(acceleration)
+    led.plotAll()
+})
+```
+
+**Challenge 1**
+
+![](/static/mb/lessons/glowing-pendulum-0.jpg)
+
+Hold the BBC micro:bit in your hand in a dark room. Move the BBC micro:bit like a pendulum, and produce a slow image that captures the pattern of the BBC micro:bit LEDs.
+
+**Challenge 2**
+
+Replace "y" in `[input->acceleration("y")] with "x" or "z". Changing the axis will cause the BBC micro:bit to measure the force in a different direction. What differences in the resulting pattern does this replacement make?
+