Which of the following examples shows that a chemical reaction has occurred? O A solid is formed when heat is removed from a sample of water.
A rock breaks into smaller pieces when it is struck with a hammer.
O A cup of water turns pink when a few drops of red food coloring are added.
Bubbles form when baking soda is added to vinegar and mixed.

Amachinist turns the power on to a grinding wheel, at rest, at time t = 0 s. the wheel accelerates uniformly for 10 s and reaches the operating angular velocity of 96 rad/s. the wheel is run at that angular velocity for 40 s and then power is shut off. the wheel slows down uniformly at 1.5 rad/s2 until the wheel stops. in this situation, the time interval of deceleration is closest to: