The number of degrees of freedom of the linkage shown in the figure is

Figure shows a wheel rotating about O₂. Two points A and B located along the radius of wheel have speeds of 80 m/s and 140 m/s respectively. The distance between the points A and B is 300 mm. The diameter of the wheel (in mm) is __________

A slider-crank mechanism with crank radius $$60$$mm and connecting rod length $$240$$mm is shown in figure. The crank is rotating with a uniform angular speed of $$10$$ rad/s, counter clockwise. For the given configuration, the speed (in m/s) of the slider is ____________.

An offset slider - crank mechanism is shown in the figure at an instant. Conventionally, the Quick Return Ratio (QRR) is considered to be greater than one. The value of QRR is _______