A 139-turn circular coil of radius 2.13 cm is immersed in a uniform magnetic field that is perpendicular to the plane of the coil. during 0.175 s the magnetic field strength increases from 57.7 mt to 92.1 mt. find the magnitude of the average emf, in millivolts, that is induced in the coil during this time interval.

You have two photos of a person walking. one shows the person at the corner of third and main streets, the other shows the person at the corner of tenth and main streets. there are lampposts at every corner in this town, and the first picture shows it to be 10: 32: 00 exactly. the second picture shows it to be 10: 49: 30. you know three facts: (1) all of the clocks are synchronized; (2) there are exactly 12 equal-sized blocks per kilometer in this town; and (3) the streets that cross main in this area are numbered consecutively, with no interruptions. what is the person’s average speed in kilometers per hour?