What characteristics do all minerals share

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:

Give one example to show that when substances are mixed,it may result in a chemical or a physical change depending on the conditions.

If two parallel light rays hit a mirror, they will not be parallel to each other after they reflect.