Imagine a helicopter hovering at a small height above a man

Last updated: 6/10/2023

Imagine a helicopter hovering at a small height above a man standing on the ground Helicopter rotor has two identical blades Man is looking directly towards helicopter We refer to the actual direction of rotation of blades as true direction Assume human eyes takes fifteen pictures or frame per second A If rotor is rotating at 90 rad s blades will appear to him rotating in true direction B If rotor is rotating at 90 rad s blades will appear to him rotating opposite to true direction C If rotor is rotating at 195 rad s blades will appear to him rotating in true direction D If rotor is rotating at 195 rad s blades will appear to him rotating opposite to true direction