A body travels a distance of $3 \mathrm{km}$ towards East, then $4 \mathrm{km}$ towards North and finally $9 \mathrm{km}$ towards East. What is the total distance travelled?

A boy walks from his classroom to the bookshop along a straight corridor towards North. He covers a distance of $20 \mathrm{m}$ in $25$ seconds to reach the bookshop. After buying a book, he travels the same distance in the same time to reach back to the classroom. Find:

$1.$ Average speed

$2.$ Average velocity, of the boy.

A body goes round the sun with constant speed in a circular orbit. Is the motion uniform or accelerated?