You program a dot on a computer screen to have a position given by
. At time
the dot's displacement from its t = 0 position has a magnitude 10.0cm a.) Find the magnitude and direction of the average velocity of the dot between t = 0 and
. b.) find the magnitude and direction of the instantaneous velocity at t = 0 and at
the answer is
a.) 5.0cm/s 37 degrees
b.) t = 0: 3.0cm/s, 90 degrees
t_{10} : 8.5cm/s,21 degrees
im stuck with the letter a what i did was substitute 10 as t and got 201.5 as V2 and i got 19.2cm/s as the average velocity
HELP