In a rack and pinion system, rack is an element moving in translational direction and pinion is a rotary gear. Which one of the following statements is correct?

Concept:

Translation acceleration a_t is given by;

a_t = R α

And,

Torque (T) = Iα 

Now, combining the above two equation we get

∴  

∴ From the above equation, we can see that a_t is inversely proportional to the moment of inertia.

Hence in a rack and pinion system when the rack is moving in translational direction and pinion is rotating then translational acceleration is inversely proportional to the moment of inertia of pinion.