Rewrote in simple language. API might not be functional.

docs/reference/input/magnetic-force.md

@@ -1,27 +1,35 @@
 # Magnetic Force
 
-Get the magnetic force (micro Teslas), in one of three specified dimensions.
+Find the amount of magnetic force (the strength of a magnet) in the direction you say.
 
 ```sig
 input.magneticForce(Dimension.X);
 ```
 
+## ~hint
+
+The micro:bit measures magnetic force with **microteslas**.
+
+## ~
+
+
 ### Parameters
 
-* dimension : [String](/reference/types/string) - one of three values specifying the axis of the force: ``x`` (left/right); ``y`` (forward/backwards); ``z`` (up/down); ``strength`` (the length of the vector)
+* a [string](/reference/types/string) that says which direction the micro:bit should measure magnetic force in: either `x` (the left-right direction), `y` (the forward/backward direction), or `z` (the up/down direction)
 
 ### Returns
 
-* [Number](/reference/types/number) - magnetic force, in micro-Teslas.
+* a [number](/reference/types/number) of microteslas that means the strength of the magnet
 
 ### Example: metal detector
 
-The following example uses the `magnetic force` to control the brightness of the screen. When the magnetic force increases, the center LED will appear brighter.
+This program makes the center LED of the micro:bit get brighter when
+the magnetic force is stronger, and dimmer when it is weaker.
 
 ```blocks
 led.plot(2, 2)
 basic.forever(() => {
-    let f = input.magneticForce(Dimension.X)
+    let f = input.magneticForce("x")
     led.setBrightness(f / 2000)
 })
 ```
@@ -29,4 +37,3 @@ basic.forever(() => {
 ### See also
 
 [compass heading](/reference/input/compass-heading)
-