How to calculate radius of the wheels to overcome the obstacle?

[joonsun4u]

Hi to all.
Please help me to clarify this situation:

There is a 4-wheel cart powered by friction drive using the dc motor. The cart will carry heavy stuffs on the top. what radius of wheels will be able to overcome a 1 cm high and 0.7 cm wide and 14 cm long speed bump(like a thin stick)?

For ex. here are some data based on the picture attached.
r1 = 0.0475 inch
w1 = 490 rad/s
w2= don't know.
r2= don't know, r2 is what i am trying to calculate.
mg= (5kg) (9.8)


Which formulas must I use to determine appropriate radius of wheel to overcome the speed bump easily?

Thank you all for help!
how to calculate radius of the wheels to overcome the obstacle?

 

[Danger]

Welcome to PF, Joonsun.
I don't think that the radius is anywhere near as important as tread design and motor/gearbox output.

 

[ACPower]

I think the problem you want to consider is something like this:
Consider that the point of contact with the obstacle and the wheel is now a pivot point, and you want the motor to supply enough torque to lift the entire cart, using the radius of the wheel as the length of the lever. This only works if the wheel doesn't slip, and the slipping will depend on the normal force at the contact, which will depend on the height of the obstacle and the wheel radius...