The displacement of the reciprocating roller follower, when it has contact with the straight flanks of the tangent cam, is given by (where r₁ = Minimum radius of the cam, r₂ = Radius of the roller follower, and θ = Angle turned by the cam from the beginning of the follower displacement)

• A. (r₁ + r₂) (1 + cosθ)
• B. (r₁ - r₂) (1 - cosθ)
• C. (r₁ - r₂) [(1 - cosθ)/cosθ]
• D. (r₁ + r₂) [(1 - cosθ)/cosθ]

Answer: (D)