Now, \(\mathbfu \cdot \mathbfw = \mathbfu \cdot \mathbfw_\parallel + \mathbfu \cdot \mathbfw_\perp = \mathbfu \cdot \left(\frac23 \mathbfv\right) + \mathbfu \cdot \mathbfw_\perp = \frac23 (\mathbfu \cdot \mathbfv) + \mathbfu \cdot \mathbfw_\perp = \frac23(1) + \mathbfu \cdot \mathbfw_\perp = \frac23 + \mathbfu \cdot \mathbfw_\perp. - Portal da Acústica