Setup and procedure

Setup

  • Review Newton’s Laws of Motion and make some predictions about what will happen if you drop objects with different mass and acceleration.
  • Create hypotheses around what types of designs might minimize force of collision.
  • Group students to begin work on egg carriers.
  • Code the micro:bit and perform a series of tests dropping the micro:bit in the carriers from a height.
  • Once the test results are successful, insert the egg into the carriers and drop from a height.
  • Debrief on the results - which carriers were the most successful? Why?

Code

This project will use the micro:bit to test the force of collision.

  • From the ||input:Input|| Toolbox drawer, drag an ||input:on shake|| block to the workspace
  • Use the drop-down menu to select 8g. This block will detect when a force 8g or greater is exerted on the micro:bit.
input.onGesture(Gesture.EightG, function () {

})

Gravitational Force

The g-force or gravitational force is a measure of gravitational force where an object at rest on the Earth’s surface is subject to 1 g of force. So, 8g = 8 times the normal gravitational force exerted on an object.

  • From the ||basic:Basic|| Toolbox drawer, drag a ||basic:show leds|| block and drop it into the ||input:on 8g|| block.
  • Draw an X or other symbol to indicate that the micro:bit has experienced 8g of force.
input.onGesture(Gesture.EightG, function () {
basic.showLeds(`
# . . . #
. # . # .
. . # . .
. # . # .
# . . . #
`)
})

Now let’s add some code to reset our experiment.

  • From the ||input:Input|| Toolbox drawer, drag an ||input:on button pressed|| block to the workspace.
input.onButtonPressed(Button.A, function () {

})
  • From the ||basic:Basic|| Toolbox drawer, drag a ||basic:clear screen|| block and drop it into the ||input:on button pressed|| block.
input.onGesture(Gesture.EightG, function () {
basic.showLeds(`
# . . . #
. # . # .
. . # . .
. # . # .
# . . . #
`)
})
input.onButtonPressed(Button.A, function () {
basic.clearScreen()
})

Sample code file: https://makecode.microbit.org/_L96ELqWtrV65

Download the code onto the micro:bit, and then connect the micro:bit to a battery pack.

Conducting the Experiment

After coding the micro:bit and constructing the egg drop carriers, take turns testing dropping the micro:bit in the carriers from a height. Do the micro:bit lights turn on? If so, that means the force exerted on the micro:bit was at least 8g – a good indication that the egg most likely will break on impact. Continue refining the egg drop carriers until no micro:bit lights turn on when dropped. Then test with an egg!

Debrief

Discuss the results of the experiment:

  • Which egg carriers were successful? Which were not?
  • Are there patterns you can identify between the carrier designs?
  • Were the micro:bit test results a good indication of whether the egg would break or not?
  • How might you find out exactly how much g-force would need to be exerted to break the egg?
  • Thinking about Newton’s Laws of Motion, what principles can you deduce about how to minimize the force of impact?

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