Question 2
Tick all the correct statements below:
1. a flow is undergoing a strain deformation whenever the divergence of the velocity is nonnull
2. a flow is undergoing a strain deformation whenever the Jacobian of the velocity is symmetric
3. a flow is undergoing a strain deformation whenever the non-diagonal elements of the Jacobian of the velocity are nonnull and symmetric
4, a flow is undergoing a strain deformation whenever the curl of its velocity is nonnull