What are the conditions for a flow to be irotational flow​

Rotation of a fluid particle can be caused only by a torque applied by shear forces on the sides of the particle. Since shear forces are absent in an ideal fluid, the flow of ideal fluids is essentially irrotational. Generally when the flow is viscid, it also becomes rotational

u=13

v=30

s/t=u+1\2at

=13+431/2

=13+265.5

=278.5

ice to water 1 water to vapour 2 latent heat