1. **State the problem:** A body of mass 0.6 kg is thrown vertically upwards with a speed of 20 m/s. We need to calculate its kinetic energy. 2. **Formula used:** The kinetic energy (KE) of an object is given by the formula: $$ KE = \frac{1}{2} m v^2 $$ where $m$ is the mass and $v$ is the velocity. 3. **Substitute the values:** $$ KE = \frac{1}{2} \times 0.6 \times 20^2 $$ 4. **Calculate the velocity squared:** $$ 20^2 = 400 $$ 5. **Calculate kinetic energy:** $$ KE = \frac{1}{2} \times 0.6 \times 400 $$ 6. **Simplify step-by-step:** $$ KE = 0.3 \times 400 $$ $$ KE = 120 $$ 7. **Final answer:** The kinetic energy of the body is **120 joules**.