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

Explanation

We have to project water achieving max.y for given `x=8 m`
This can be solved by using equation of trajectory by putting `x=8` m and maximizing y by varying `theta`.
By `y=x tan theta-(gx^(2))/(2u^(2) cos^(2) theta)` Here `x=8m, u=20 m//s`
`y=8 tan theta-(10xx64(1+tan^(2) theta))/(2xx400)`
`0.8 tan^(2) theta-8 tan theta+(y+0.8)=0`
for `theta` real `b^(2)-4xx0.8(y+0.8) ge 0`
`y_("max")=19.2 m`