Dynamics

[Elson]

Hello, does anyone know how to do this question?

 

Gear A (radius = 150mm, mass= 4kg and radius of gyration = 100mm) and gear B(radius = 450mm, mass= 10kg and radius of gyration= 300mm) rotate about their respective centrers. A constant clockwise torque of 0.75Nm is applied to the gear A. neglecting bearing friction torque, determine the angular acceleration of each gear and the tangential contact forces between the gears.

[insane_alien]

well, what working have you done so far?

 

we will help you answer the question but we don't just give out the answer to homework questions.

 

you'll need the formulae for angular acceleration and torque.

[Elson]

Well i used torque = I(moment of inertia) x a(angular acceleration)

0.75 = (1/2)(4)(0.01) x a, a = 0.75/0.02, a=37.5 but the answer is 5.4rad/s2.

As for the tangential contact forces, i have no idea about that. I was informed late by the University and missed the class for 2 weeks. Need help from you guys.. thanks!

[insane_alien]

torque is also Force times radius. try working with that.

[Elson]

How bout torque = force times radius = ma times radius ->mra times radius.

torque = 2I times angular acc? For gear A, 0.75= 2(0.02) times angular acc. Therefore i get angular acc = 0.75/0.04 = 18.75?