Changing the positive direction in a reference frame to the opposite direction does not change the sign of which of the following quantities?
a. velocity
c. speed
b. average velocity
d. displacement
Question 2
A ball is thrown vertically upwards at 9.8 m/s. For its complete trip (up and back down to the starting position), its average velocity is:
a. 19.6 m/s.
c. 4.90 m/s.
b. 9.80 m/s.
d. not given.