Mechanical waves travel faster through than through

a. liquids, solids
b. solids, liquids
c. a vacuum, air
d. air, liquids

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.

A6.0-μf air-filled capacitor is connected across a 100-v voltage source. after the source fully charges the capacitor, the capacitor is immersed in transformer oil (of dielectric constant 4.5). how much additional charge flows from the voltage source, which remained connected during the process?

A15 ohm resistor and a 25 ohm resistor are connected in a series to a 60 volt battery. what is the power used by each device