\({\overrightarrow v _2} = - 20\hat i\)
\(\Delta \overrightarrow v = {\overrightarrow v _2} - {\overrightarrow v _1} = - 20(\hat i + \hat j)\)
\(|\Delta \overrightarrow v |\, = \,20\sqrt 2 \)and direction \(\theta = {\tan ^{ - 1}}(1) = 45^\circ \) i.e. S-W