Question

A child is sitting on a swing. Its minimum and maximum heights from the ground 0.75 m and 2 m respectively, its maximum speed will be

• A. 10 m/s
• B. 5 m/s
• C. 8 m/s
• D. 15 m/s

Answer 1

Answer: (B)

5 m/s

Answer 2

Drop in P.E = maximum K.E.
mg (2 - 0.75) = 1 mv$^2 \, \, \Rightarrow \, \, \, v=\sqrt{2g(1.25)} = 5\,m/s$.