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Question
A mass of 5 kg is moving along a circular path of radius 1 m. If the mass moves with 300 revolutions per minute, its kinetic energy would be ______.
Options
250 π2
100 π2
5 π2
0
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Solution
A mass of 5 kg is moving along a circular path of radius 1 m. If the mass moves with 300 revolutions per minute, its kinetic energy would be `underline(250 π^2)`.
Explanation:
Given, mass = m = 5 kg
Radius = 1 m = R
Revolution per minute ω = 300 rev/min
= (300 × 2π) rad/min
= (300 × 2 × 3.14) rad/60 s
= `(300 xx 2 xx 3.14)/60` rad/s
= 10 × rad/s
⇒ Linear speed = v = ωR
= `((300 xx 2π)/60) (1m)`
= 10π m/s
KE = `1/2 mv^2`
= `1/2 xx 5 xx (10π)^2`
= `100π^2 xx 5 xx 1/2`
= 250 π2 J
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