A particle moves in a circle of radius $5 \mathrm{~cm}$ with constant speed and time period $0.2 \pi…

A particle moves in a circle of radius $5 \mathrm{~cm}$ with constant speed and time period $0.2 \pi \mathrm{s}$. The acceleration of the particle is
  1. $25 \mathrm{~m} / \mathrm{s}^2$
  2. $36 \mathrm{~m} / \mathrm{s}^2$
  3. $5 \mathrm{~m} / \mathrm{s}^2$
  4. $15 \mathrm{~m} / \mathrm{s}^2$

Solution

Given, $r=5 \mathrm{~cm}=5 \times 10^{-2} \mathrm{~m}$ and $T=0.2 \pi \mathrm{s}$ We know that acceleration $\begin{aligned} a & =r \omega^2 \\ & =\frac{4 \pi^2}{T^2} r \\ & =\frac{4 \times \pi^2 \times 5 \times 10^{-2}}{(0.2 \pi)^2}=5 \mathrm{~ms}^{-2} \end{aligned}$

Asked in: NEET 2011 (Screening)

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