Posted by Ryan Murphyon Wed 06 of Dec, 2017 23:33 EST

So you’re given the information that link 2 turns with gear 2, and link 5 turns with gear 5. This means that you can relate the angles theta 2 and theta 5 by the gear ratio. For example if your r2 is 5cm and your r5 is 15cm. This means your gear ratio is 3 to 1. For every 3 turns of gear 2, you get 1 turn of gear 5. So if your gear 2 rotates 30 degrees counter clockwise, then your gear 5 will have rotated 10 degrees clockwise (opposite directions because the gears form an external pair). These are your values for theta 2 and theta 5 respectively.