The position of a particle is given by r = 4ti +2t^2j)m. Its Y component of velocity at t =1s is

position vector,  r = ( 4t i + 2t² j  ) m

 

velocity vector,  dr/dt = ( 4 i + 4t j ) m

 

y- component, v_y = 4t ;   y-component at t =1 s  ,   v_y = 4×1 = 4 m/s