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A motor rotates a pulley of radius 25cm ...

A motor rotates a pulley of radius `25cm` at 20rpm. A rope around the pulley lifts a `50kg` block, What is the power output of the motor?

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The tension in the rope is equal to the weight since there is no acceleration

Thus , T = 500 N
Therefore , `tau = TR = (500) (0.25) = 125 Nm`
Angular velocity , `omega = (2piN)/60 ` or
` omega = (2pi(20))/60 = (2pi)/3 `rad/s
the power required is
`P = tau omega = (125 Nm) ((2pi)/3 rad//s) = 260 N `
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NARAYNA-SYSTEM OF PARTICLES AND ROTATIONAL MOTION -EXERCISE - IV
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  8. The density of a non-uniform rod of length 1m is given by rho (x) = a ...

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  9. A Merry -go-round, made of a ring-like plarfrom of radius R and mass M...

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  10. Choose the correct alternative :

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  11. Figure shows two identical particles 1 and 2 , each of mass m ...

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  13. A uniform cube of mass m and side a is placed on a frictionless ...

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  14. A uniform uniform sphere of mass m and radius R is placed on a ro...

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  15. A T shaped object with dimesions shown in the figure , is lying a...

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  16. A circular ring of mass 6kg and radius a is placed such that its cente...

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  17. In the figure d shown a hole of radius 2 cm is made in a semicir...

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  18. The figure shows the positions and velocities of two particles . ...

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  19. A rod of length 3m and its mass par unit length is directly propo...

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  20. A wheel is rotating about an axis through its centre at 720 rp...

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