Available since LÖVE 0.8.0  
 This method is not supported in earlier versions. 
Returns the current joint translation speed.
speed = WheelJoint:getJointSpeed( )
None.
number speed
 
    © 2006–2016 LÖVE Development Team
Licensed under the GNU Free Documentation License, Version 1.3.
    https://love2d.org/wiki/WheelJoint:getJointSpeed