Answer:
the uncertainty in the distance measurement is 0.5148
Explanation:
Given the data in the question;
uncertainty in locating the center of the magnet is estimated to be 0.25 cm,
uncertainty in locating the position of the sensor in the phone is estimated to be 0.45 cm,
Using quadrature method, uncertainty in the distance measurement = ?
We know that;
Using  quadrature method, Combined Uncertainty calculated by;
U[tex]_c[/tex] = â( Uâ² + Uâ² + ........... )
where Uâ is uncertainty in first measurement and Uâ is uncertainty in second measurement, et cetera.
now we substitute;
U[tex]_c[/tex] = â( Uâ² + Uâ² )
U[tex]_c[/tex] = â( (0.25)² + (0.45)² )
U[tex]_c[/tex] = â( 0.0625 + 0.2025 )
U[tex]_c[/tex] = â( 0.265 )
U[tex]_c[/tex] = 0.5148
Therefore, the uncertainty in the distance measurement is 0.5148