What is a correct equation for acceleration?

1. how to locate the image in converging(concave) mirror and diverging (convex) mirror with salt. 2. how to locate the image in a converging (convex) lens and diverging (concave) lens with salt.

Avehicle accelerates from 0 to 30 m/s in 10 seconds on a straight road

Describe how the motion of a spring being pushed forward and backward is similar to the motion of air particles in a sound wave.