How do ions help your brain?

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.

An automobile steering wheel is shown. what is the ideal mechanical advantage? if the ama is 8, what is the efficiency of the steering wheel?

How will the system respond to a temperature increase?