Correct Answer - Option 1 : Normalised acceleration on the return part

**Explanation:**

**Spline Cam:** The spline method of designing cams is based on using cubic polynomials to fit a given displacement diagram at a predetermined number of points. This method is used for designing nonstandard cams.

The **normalized velocities and accelerations** for a spline cam are, respectively, as follows

**On the rise part:**

**Velocity**

\(\dot {\bar u_1} = \dot {\bar u_2} = \frac {\dot {u}\theta_A}{2L}\)

**Acceleration**

\(\ddot {\bar u_1} = \ddot {\bar u_2} = \frac {\ddot {u}\theta_A ^2}{4L}\)

**On the return part:**

**Velocity**

\(\dot {\bar u_4} = \dot {\bar u_5} = \frac {\dot {u}(\theta_B - \theta _C)}{2L}\)

**Acceleration**

\(\ddot {\bar u_4} = \ddot {\bar u_5} = \frac {\ddot {u}(\theta_B - \theta _C)^2 }{4L}\)