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Question

A car accelerates from 8m/s at 2m/s2 for 5s, then moves at constant speed for 3s. What is the average speed over the entire motion?

Options

Choose one · Correct answer highlighted

Explanation

Phase 1: v=8+2⋅5=18m/s, x1=8⋅5+12⋅2⋅(5)2=40+25=65m. As per NCERT Chapter 3, equations v=u+at, s=ut+½at², v²=u²+2as describe uniformly accelerated motion. Applying correct signs and units gives 15 m/s as the result, so option B is correct.