Question

A bird files due north at velocity 20 `ms^(-1)` for 15s it rests for 5s and then files due south at velocity `24 ms^(-1)` for 10s. For the whole trip find the average speed and magnitude of average velocity

Answer 1

Average speed = `("Total Distance")/("Total Time") = ( 20 xx 15 + 24 xx 10)/( 15 + 5 + 10) = (540)/(30) = 18 m//s`
Average velocity = `("Displacement")/("Total Time")= ((20 xx 15) hatj + ( 24 xx 10)(-hatj))/(15+ 5 10) = (60 hatj)/(30) = 2hatj`
Magnitude of average velocity = `|2 vecj| = 2m//s`