During an observation, a bird first moves 120m due East and then 90m due North in a single flight.
a. (i) Treating the two straight-line segments as the rectangular components of a single displacement, calculate the magnitude of the bird’s resultant displacement.
b. (ii) Determine the angle that this displacement makes with the East direction, giving your answer correct to one decimal place.
c. (iii) Express the resultant displacement in unit-vector notation.