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⚛️ Physics  ·  Motion in a Straight Line  ·  NEET & JEE

A car covers the first half of a distance at 40 km/h and the second half at 60 km/h. Its average speed for the whole trip is:

Answer: 48 km/h.

  • A 50 km/h
  • B 48 km/h
  • C 45 km/h
  • D 52 km/h

Correct answer: B. 48 km/h

Explanation: For equal distances, average = 2·40·60/(40+60) = 4800/100 = 48 km/h.

tvuvTΔtΔvslope = aarea = displacement (s)

On a velocity-time graph for uniform acceleration, the slope of the line gives the acceleration and the shaded area under the line gives the displacement.

Concept context

Equations of motion, projectile motion, relative velocity. Foundation of all mechanics.

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