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

A particle moves along x-axis with x = 3t² - 4t + 1 (in meters, t in seconds). Velocity at t=2 s is:

Answer: 8 m/s.

  • A 4 m/s
  • B 8 m/s
  • C 10 m/s
  • D 12 m/s

Correct answer: B. 8 m/s

Explanation: v = dx/dt = 6t - 4. At t=2: v = 12-4 = 8 m/s.

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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