PLEASE HELP ME!! a police car moves at a speed of 30m / s, the driver is at a single-note frequency of 650Hz It is heard. One of the police cars passes in front of someone waiting at the traffic light. approaching the other. a) approaching, b) moving away sirens wavelengths and frequencies You calculate.

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?