Bill and Ted are falling into hell at a constant speed (terminal velocity), and are screaming at the frequency f0. As they fall, they hear their own voices reflecting back to them from the puddle of molten rock that lies below at a frequency of 2f0. How fast are they falling relative to the speed of sound in warm, dry hellish air

How does the image distance (di) of a convex lens compare with the image distance of a concave lens? a. the image distance of the convex lens is positive, and that of the concave lens is negative. b. both are negative for a virtual image. c. both are positive for a virtual image d. the image distance of the convex lens is negative, and that of the concave lens is positive.

In the circuit shown below, with each bulb holding a resistance of 60 ohms, how many amps of current are flowing? express your number as a decimal.

If the ama of the inclined plane below is 2, calculate the ima and efficiency. ima = efficiency =