Verified Solution • 2025–26 Session moderate

QJEEM21Ph1d95: JEE Main 2021 Physics - Class 11 JEEM21Ph1d95 Solution: The angular speed of truck wheel is increased from 900 rpm to…

The angular speed of truck wheel is increased from 900 rpm to 2460 rpm in 26 seconds. The number of revolutions by the truck engine during this time is _____________. (Assuming the acceleration to be uniform).

Step-by-Step Verified Solution

ωf=2460×2π60{\omega _f} = 2460 \times {{2\pi } \over {60}}

=82π= 82\pi

ωi=900×2π60=30π{\omega _i} = {{900 \times 2\pi } \over {60}} = 30\pi

α=ωf−ωit\alpha = {{{\omega _f} - {\omega _i}} \over t}

=82π−30π26= {{82\pi - 30\pi } \over {26}}

= 2 π\pi rad/sec2

θ=ωf2−ωi22α\theta = {{\omega _f^2 - \omega _i^2} \over {2\alpha }}

=(82π+30π)(82π−30π)2×2π= {{(82\pi + 30\pi )(82\pi - 30\pi )} \over {2 \times 2\pi }}

=(112×52)π24π= {{(112 \times 52){\pi ^2}} \over {4\pi }}

No. of revolution =(112×13)π2π= {{(112 \times 13)\pi } \over {2\pi }}

= 728

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