Average Speed and Velocity: Practice Problem & Solution

Solution Explained:

To solve this problem, we apply the core principles of Average Speed and Velocity. Understanding the underlying formula is key to arriving at the correct answer below:

For equal distances covered in two halves of a journey, average speed is \(v_{\text{avg}} = \frac{2v_1v_2}{v_1+v_2}\). Here, \(v_{\text{avg}} = \frac{2 \times 20 \times 40}{20+40} = \frac{80}{3}\text{ ms}^{-1}\).