Answer
given,
Weight of the child = 110 N
length of the swing,L = 2 m
now, calculating the potential energy when the string is horizontal
Potential energy = m g h
now, h = L (1 - cos θ) where θ is the angle made by the string with the vertical.
PE = m g L (1 - cos θ)
when rope is horizontal θ = 90°
PE = 110 x 2 (1 - cos 90°)
PE = 220 J
now, calculating potential energy when string made 25° with horizontal
PE = m g L (1 - cos θ)
when rope is horizontal θ = 25°
PE = 110 x 2 (1 - cos 25°)
PE = 20.61 J
Answer:
C. wavelength = speed/frequency
Explanation: I got it right
