JEE Main 2024 · 6 April · morning · Numerical answer · +4 / −1

A particle is doing simple harmonic motion of amplitude 0.06 m and time period 3.14 s. The maximum velocity of the particle is _________ cm / s.

Answer and solution

Answer 12

Solution

Physics sir · 3 steps

With T = 3.14 s, the angular frequency comes out to exactly 2, so the speed follows at once.

  1. Angular frequency. For SHM, ω = 2π/T. With T = 3.14 s and π ≈ 3.14, this gives ω = (2 × 3.14)/3.14 = 2 rad s⁻¹.
  2. Maximum speed. The particle is fastest at the mean position, where all the energy is kinetic. There the speed is the amplitude times the angular frequency.

    vₘₐₓ = Aω = 0.06 m × 2 s⁻¹ = 0.12 m s⁻¹

  3. So. Converting to cm, 0.12 m s⁻¹ = 12 cm s⁻¹, so the answer is 12.

The common slip: 0.12. Leaving the answer in metres per second gives 0.12, not 12. Multiply by 100 to convert to cm/s.

The idea to keep. In SHM the top speed is always Aω, reached at the mean position. Find ω = 2π/T first, then watch the units the answer asks for.

Answer from the NTA final answer key. Solution by PrepWiser.

Study Simple Harmonic Motion

Asked about 130 times in JEE Main since 2020. This question is from 2024.