Gear ratio requirement (RPM --> km/h)

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
2 replies · 4K views
D.B0004
Messages
16
Reaction score
0

Homework Statement


A vehicle having wheels with a diameter of 58cm, is powered by motors that have a maximum speed of 6024 rpm. Each motor is coupled to the wheel using a gear mechanism as shown in figure 2-14. Calculate the required gear ratio if the vehicle's maximum speed is 190.2 km/hr.

Note: Answer is a unitless value, correct upto two decimals.

Homework Equations


No clue. C = 2 * PI * R?

The Attempt at a Solution


I converted 6024 rpm to radians per second hoping I could do the same with hm/hr, but I do not know the radius of the tire? See photo attache for diagram. Thanks for help.
 

Attachments

  • Screen Shot 2015-02-05 at 7.10.24 PM.png
    Screen Shot 2015-02-05 at 7.10.24 PM.png
    11.1 KB · Views: 1,275
  • equations.png
    equations.png
    18.7 KB · Views: 3,046
Physics news on Phys.org
D.B0004 said:

Homework Statement


A vehicle having wheels with a diameter of 58cm, is powered by motors that have a maximum speed of 6024 rpm. Each motor is coupled to the wheel using a gear mechanism as shown in figure 2-14. Calculate the required gear ratio if the vehicle's maximum speed is 190.2 km/hr.

Note: Answer is a unitless value, correct upto two decimals.

Homework Equations


No clue. C = 2 * PI * R?

The Attempt at a Solution


I converted 6024 rpm to radians per second hoping I could do the same with hm/hr, but I do not know the radius of the tire? See photo attache for diagram. Thanks for help.
... but you know the diameter of the wheel. How is diameter related to radius?...
 
I converted 6024 rpm to radians per second...

I would start "at the other end of the problem". eg Work out the rpm of the wheel at max velocity.