In orthogonal turning of a bar of $100$ $mm$ diameter with a feed of $0.25$ $mm$/$rev$, depth of cut of $4$ $mm$ and cutting velocity of $90$ $m$/$min$, it is observed that the main (tangential) cutting force is perpendicular to the friction force acting at the chip-tool interface. The main (tangential) cutting force is $1500$ $N$.

The orthogonal rake angle of the cutting tool in degree is

1. zero
2. $3.58$
3. $5$
4. $7.16$