A person travelling in a straight line moves with a constant velocity v₁ for a certain distance x and with a constant velocity v₂ for the next equal distance. The average velocity v is given by the relation:
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Question

A person travelling in a straight line moves with a constant velocity v₁ for a certain distance x and with a constant velocity v₂ for the next equal distance. The average velocity v is given by the relation:

Options

G1 Physics · Accepted Answer

Step 1: The two equal distances are x and x, so total distance is 2x. Step 2: Total time = x/v₁ + x/v₂. Step 3: v = 2x/[x/v₁+x/v₂] = 2v₁v₂/(v₁+v₂). Rearranging gives 2/v = 1/v₁ + 1/v₂. Final answer: B.