Velocity of the sled is 3.2 m/s
Answer:
13.4cm
Explanation:
According to Rayleigh’s criterion the angular resolution to distinguish two objects is given by:

θ = 50.0*10^-7 rad
λ: wavelength of the light = 550nm
b = diameter of the objective
By doing b the subject of the formula and replacing the values of the angle and wavelength you obtain:

hence, the smallest diameter objective lens is 13.4cm
Assuming motion is on a straight path, the result of two positive components of a vector would also be a positive value since both are having positive signs and directions. The direction would be the same with the motion as well. Hope this answers the question. Have a nice day.