A person covers half a straight-road distance at speed v₁ and the remaining half at speed v₂. Express the average speed over the whole journey.
Physics · Mixed Chapter
JEE Main Practice

Question

A person covers half a straight-road distance at speed v₁ and the remaining half at speed v₂. Express the average speed over the whole journey.

G1 Physics · Accepted Answer

Step 1: Let total distance be D, so each leg has distance D/2. Step 2: Times t₁=D/(2v₁), t₂=D/(2v₂). Step 3: Average speed vₐᵥ =D/(t₁+t₂)=2v₁v₂/(v₁+v₂). Step 4: Original PDF prints numeric key 4 but does not define a numeric target or assign numerical v₁ and v₂; key cannot be independently verified.