The number of degrees of freedom of the planetary gear train shown in the figure is

A wheel of radius r rolls without slipping on a horizontal surface shown below. If the velocity of point P is 10m/s in the horizontal direction, the magnitude of velocity of point Q (in m/s) is ______

A 4-bar mechanism with all revolute pairs has link lengths $${l_f} = 20\,\,mm,\,\,{l_{in}} = 40\,\,mm,\,\,{l_{co}} = 50mm$$ and $${l_{out}} = 60\,mm.$$ The suffixes $$'f', 'in', 'co'$$ and $$'out'$$ denote the fixed link, the input link, the coupler and output link respectively. Which one of the following statements is true about the input and output links?

A rigid link PQ is 2 m long and oriented at 20^o to the horizontal as shown in the figure. The magnitude and direction of velocity V_Q, and the direction of velocity V_P are given. The magnitude of V_P(in m/s) at this instant is