What have been the first step in forming the solar system

How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects

The uniform slender bar rests on a smooth horizon- tal surface when a force f is applied normal to the bar at point a. point a is observed to have an initial acceleration aa of 20 m/s2, and the bar has a corre- sponding angular acceleration of 18 rad /s2. deter- mine the distance b.

What distance does a car travel as its speed changes from 0 to 20 m/s in 17 s at constant acceleration?