Both free vortex and forced vortex can be expressed mathematically in terms of tangential velocity V at the corresponding radius r. Choose the correct combination
- A. Free: V = r $\times$ const, Forced: V $\times$ r = const
- B. Free: $V² \times r$ = const, Forced: V = r $\times$ const
- C. Free: V $\times$ r = const, Forced: $V²$ = r $\times$ const
- D. Free: V $\times$ r = const, Forced: V = r $\times$ const
Answer: D. Free: V $\times$ r = const, Forced: V = r $\times$ const
Explanation: Free vortex: Angular momentum is constant ($vr = C$). Forced vortex: Rigid body rotation ($v = r\omega \rightarrow v = r \times C$).