Practice 1:
Practice 2:
Practice 3:
Practice 4:
When .
Practice 5: so
so .
When (See Fig. 12)
Practice 6: When : pos., pos., pos. When : pos., neg., neg.
Practice 7: and so and Then
speed
, a constant.
Practice 8: and so and Then
speed .
When , the speed is .
When , the speed is (faster).