Question

Explain the similarities and differences of centripetal and centrifugal forces.

Answer 1

Salient features of centripetal and centrifugal forces.
Centripetal Force:

• It is a real force that is exerted on the body by external agencies like gravitational force, the tension in the string, normal force, etc.
• Acts in both inertial and non-inertial frames
• It acts towards the axis of rotation or center of the circle in a circular motion
  `|vecF_{C_P}|` = mω²r = `(mv^2)/r`
• Real force and has real effects
• The origin of centripetal force is the interaction between two objects.
• In inertial frames centripetal force has to be included when free body diagrams are drawn.

Centrifugal Force:

• It is a pseudo force or fictitious force which cannot arise from gravitational force, tension force, normal force, etc.
• Acts only in rotating frames (non-inertial frame)
• It acts outwards from the axis of rotation or radially outwards from the center of the circular motion
  `|vecI_{C_f}|` = mω²r = `(mv^2)/r`
• Pseudo force but has real effects
• The origin of centrifugal force is inertia. It does not arise from the interaction. In an inertial frame, the object’s inertial motion appears as the centrifugal force in the rotating frame.
• In inertial frames, there is no centrifugal force. In rotating frames, both centripetal and centrifugal forces have to be included when free body diagrams are drawn.