Activity 2
Find The Coordinate System Of The Magnetometer On Your Phone
A coordinate system is a system that defines positions in space. We can take measurements according to different orientations of the coordinate system.
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Suppose we want to use our phone as a reference coordinate system to measure distances. The reference coordinate system looks like the figure below:
Based on the provided maps, answer the following questions.
How many grids in the x and y direction will you need to move to get from Purity Ice Cream to Ned’s Pizza?
Answer:
grids in +x direction and grids in +y direction.
How many grids in the x and y direction will you need to move to get from Ned’s Pizza to Cornell University?
Answer:
grids in +x direction and grids in +y direction.
Let us rotate the coordinate system by 90° counterclockwise.
How many grids in the x and y direction will someone need to move to get from Purity Ice Cream to Ned’s Pizza?
Answer:
grids in +x direction and grids in +y direction.
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The phone magnetometer works in a similar way. It has a coordinate system embedded in itself and measures the magnetic field in x and y directions, but it also measures a third direction - the z - direciton. Let’s find out the orientation of the magnetometer’s coordinate system.
Open the Phyphox magnetometer on your phone and select “Multi” in the menu. Measure the initial magnetic field and record the x, y, and z components of the magnetic field in the table.
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Place your phone on a table, hold a scissor or a metallic fork near your phone. Place the object at 2.5 cm from your phone at the three locations:
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For each component, observe the change in magnetic field at position 1, 2, and 3. Fill out the following statements.
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For the x-component, the magnetic field has the largest change at position
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For the y-component, the magnetic field has the largest change at position
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For the z -component, the magnetic field has the largest change at position
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According to the results above, label the coordinate system of the magnetometer on your phone with x, y, and z.
(1) on the upside of your phone
(2) above your phone
(3) on the right side of your phone
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Ignore the positive and negative signs for now.
