A stone of mass 1 kg is tied with a string and it is whirled in a vertical circle of radius 1m. If tension at the highest point is 14N, then velocity at lowest point will be:

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A stone of mass m kg is whirled in a verticle circle of radius 20cm. The difference in kinetic energies at the lowest and the topmost position is

The correct option is C 0.4mgJDifference in KE will be equal to Change is PE , because as stone will move to topmost position , Loss in KE= Gain in PESo,ΔKE=mgh2−mgh1 now h1=0 ,h2=2×r=0.4mΔKE=0.4mgJ

A stone of mass $m k g$ is whirled in a verticle circle of radius $20 c m$ . The difference in kinetic energies at the lowest and the topmost position is

The correct option is C $0.4 m g J$
Difference in KE will be equal to Change is PE , because as stone will move to topmost position , Loss in KE= Gain in PE
So, $Δ K E = m g h_{2} - m g h_{1}$ now $h_{1} = 0, h_{2} = 2 \times r = 0.4 m$
$Δ K E = 0.4 m g J$