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A wheel rotates with constant aceeleration of 2.0\; rad/s^2, if the wheel starts from rest the number of revolutions it makes in the first ten seconds will be approximately

Option: 1

16


Option: 2

24


Option: 3

32


Option: 4

8


Answers (1)

best_answer

As we have learned

Time period -Time taken to complete one rotation

S.I unit seconds (s)

w= \frac{2\pi }{T } \: \: \: or \; \; \frac{2\pi N}{T}

N= Number of rotation

w= 2\pi \nu 

 \nu = \frac{N}{t}

For circular/angular motion, the formula for angular displacement \theta and angular acceleration \alpha is

\theta =\omega +\frac{1}{2}\alpha t^2 

where \omega=intial angular velocity

\theta =0+\frac{1}{2}\alpha t^2=\frac{1}{2}\times(2)\times(10)^2

or

 \theta=100 \; radian

2\pi radian is covered in 1 revolution 

\therefore 1 radian is coverd in \frac{1}{2\pi} revolution 

 100 radians are covered in \frac{100}{2\pi} revolution 

\therefore Number of revolution =\frac{50}{3.14}\approx 16

Posted by

Ritika Kankaria

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