A particle P P\,P moves with constant acceleration (2i−5j) ms−2(2\mathbf{i} - 5\mathbf{j}) \text{ ms}^{-2}(2i−5j) ms−2. At time t=0t = 0t=0, P P\,P has speed u ms−1u \text{ ms}^{-1}u ms−1. At time t=3 st = 3 \text{ s}t=3 s, P P\,P has velocity (−6i+j) ms−1(-6\mathbf{i} + \mathbf{j}) \text{ ms}^{-1}(−6i+j) ms−1.
Find the value of uuu.
