A trolley of mass 2kg rolls on a smooth horizontal track. Its speed changes uniformly from 3m s−1 to 11m s−1 in 4s because of a horizontal pull applied by a student. Answer the following.
a. (i) Calculate the change in momentum of the trolley during the 4s interval.
b. (ii) Find the magnitude and direction of the net horizontal force acting on the trolley.
c. (iii) If the same pull acts on another trolley of mass 4kg starting from rest, what acceleration will it produce? Show your working.