If the ratio between the frequency of a man's voice and that of a girl's voice is 3/4, what is the ratio between the speeds of the voices of the man and the girl in air ?

In a region of space, a magnetic field points in the +x-direction (toward the right). its magnitude varies with position according to the formula bx=b0+bx, where b0 and b are positive constants, for x≥0. a flat coil of area a moves with uniform speed v from right to left with the plane of its area always perpendicular to this field. part a what is the emf induced in this coil while it is to the right of the origin?