All of these are examples of chemical reactions except
a. bleach spilled on a shirt turning it from red to pink
b. flowers wilting and turning from white to brown
c. the heating element on a stove turning from black to orange

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.