Physics
A person swings on a rope from a cliff that is 20 m high. How fast is the person moving at the lowest point of the swing? (Take g=10m/s-2)
Work, Energy & Power
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Answer
As the person swings on a rope from a cliff of height h = 20 m then potential energy at the top gets converted into kinetic energy at the lowest point.
From conservation of energy,
Potential energy at top = Kinetic energy at lowest point
mgh = mv2
gh = v2
10 x 20 = v2
400 = v2
m/s
∴ The person is moving at a speed of 20 m/s at the lowest point of the swing.
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