I need help for these questions (excuse the handwriting)

Current enters a circuit at a: 1.positive terminal 2.negative terminal 3.low potential side 4.resistor

Which accurately compares concave and convex lenses?

Aclarinetist, setting out for a performance, grabs his 3.350 kg clarinet case (including the clarinet) from the top of the piano and carries it through the air with an upward force of 24.65 n. find the case's vertical acceleration. indicate an upward acceleration as positive and a downward one as negative.