NEET UG 2016 — Physics Mechanics

2016mcqhard

A particle of mass $10g$ moves along a circle of radius $6.4\mathrm{cm}$ with a constant tangential acceleration. What is the magnitude of this acceleration if the kinetic energy of the particle becomes equal to $8\times {10}^{-4} J$ by the end of the second revolution after the beginning of the motion?

Official previous-year question

Held on 30 Apr 2016 · Verified 9 Jul 2026.

Options

A
$0.18 m {s}^{-2}$
B
$0.2 m {s}^{-2}$
C
$0.1 m {s}^{-2}$
D
$0.15 m {s}^{-2}$

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Solution

Tangential acceleration ${a}_{t}=r\alpha =$ constant $=K$

$\alpha =\frac{K}{r}$

At the end of second revoluation angular velocity is $\omega$ then

${\omega }^{2}-{\omega }_{0}^{2}=2\alpha \theta$

${\omega }^{2} =2( \frac{K}{r} )( 4\pi )$

${\omega }^{2}=\frac{8\pi K}{r}$

K.E. of the particle is $=K.E.=\frac{1}{2}m{v}^{2}$

$K.E.=\frac{1}{2}m{r}^{2}{\omega }^{2}$

$\text{K}.\text{E}.=\frac{1}{2}\text{m}({r}^{2})(\frac{8\text{πK}}{r})=\frac{1}{2}mr(8\pi K)$

$8\times { 10 }^{ -4 } =\frac{1}{2} \times 10\times { 10 }^{ -3 } \times 6.4\times { 10 }^{ -2 } \times 8\times 3.14\times \text{K}$

$K=\frac{2}{6.4\times 3.14}=0.1m{s}^{-2}$

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Solution

Tangential acceleration ${a}_{t}=r\alpha =$ constant $=K$

$\alpha =\frac{K}{r}$

At the end of second revoluation angular velocity is $\omega$ then

${\omega }^{2}-{\omega }_{0}^{2}=2\alpha \theta$

${\omega }^{2} =2( \frac{K}{r} )( 4\pi )$

${\omega }^{2}=\frac{8\pi K}{r}$

K.E. of the particle is $=K.E.=\frac{1}{2}m{v}^{2}$

$K.E.=\frac{1}{2}m{r}^{2}{\omega }^{2}$

$\text{K}.\text{E}.=\frac{1}{2}\text{m}({r}^{2})(\frac{8\text{πK}}{r})=\frac{1}{2}mr(8\pi K)$

$8\times { 10 }^{ -4 } =\frac{1}{2} \times 10\times { 10 }^{ -3 } \times 6.4\times { 10 }^{ -2 } \times 8\times 3.14\times \text{K}$

$K=\frac{2}{6.4\times 3.14}=0.1m{s}^{-2}$

NEET UG 2016 — Physics Mechanics

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NEET UG 2016 — Physics Mechanics

Options

Did you get this right?

Solution

Your note

NEET UG Mechanics in other years

More NEET UG Mechanics questions

Other Physics topics for NEET UG

Electromagnetism

Modern Physics

Thermodynamics

Optics

Waves & Oscillations

Keep practicing Mechanics