Sawmills rely on electricity to run the cutting blade.
Stepping on a can is a physical change because there is no chemistry behind this. Someone is physically breaking or deforming the can. There are no chemicals or anything touching the can. The foot smashing is physical.
1) If the object changes directions with the same speed, it will be changing its velocity, because velocity is a vector, which depends on both magnitude and direction. Speed is just magnitude regardless of direction.
2) Rotational motion.
Explanation:
According to the energy conservation,



= 
= 
v = 
= 
Formula for distance from the orbit is as follows.
S = 
= 
= 
Now, relation between time and distance is as follows.
T = 

or, f =
=
= 
Thus, we can conclude that the orbital frequency for an electron and a positron that is 1.50 apart is
.