2024ScienceA bus covers the first half of a certain distance with speed v1 and the second half with a speed v2. The average speed during the whole journey is :A.<span class="math-tex">\(\frac{2 v_{1} v_{2}}{v_{1}+v_{2}} \)</span>B.<span class="math-tex">\( \frac{v_{1}+v_{2}}{2} \)</span>C.<span class="math-tex">\(\frac{v_{1} v_{2}}{v_{1}+v_{2}} \)</span>D.<span class="math-tex">\(\sqrt{v_{1} v_{2}}\)</span>Answer under review
