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Displacement in the nth second

Free notes · JEE Main Physics

Formulas

sn=u+a(n−12)s_n = u + a\left(n - \tfrac{1}{2}\right)

Displacement in the nth second

Worked example

A body starts from rest and covers 18 m in the 5th second. Find its acceleration.

  1. sₙ = u + a(n − ½) with u = 0, n = 5: 18 = a(5 − ½) = 4.5a.
  2. a = 18/4.5 = 4 m/s².

Answer: a = 4 m/s².