Question

CALC- A web page designer creates an animation in which a dot on a computer screen has position r=[4 cm + (2.5cm/s^2)t^2] i +(5.0 cm/s)t j

a) find the magnitude and direction of the dot's average velocity between t=0 and t=2. b) Find the magnitude and direction of the instantaneous velocity at t=0, t=1, and t=2.

I understand how to solve for the magnitude for each of these questions but the answer in the back of the book for t=2 direction is 27 degrees. When using SOHCAHTOA, shouldn't it be tan^-1(10/5)? but the only way to get 27 is tan^-1(5/10)

Could someone explain to me why tanx(x/y) would be the case here?

Answer 1

In the question the simple displacement is find out and average velocity is calculated and for instantaneous velocity simple dr/dt is evaluated at different values of t and direction is find out.me