Two identical blocks P and Q, each of mass 3kg, rest on the same horizontal surface. Block P has coefficients μs=0.42, μk=0.30, while block Q has μs=0.28, μk=0.20. A horizontal force of 18N is applied separately to each block starting from rest for a time interval of 5s. Take g=9.8m s−2.
(i) For each block, find whether motion starts and, if so, determine the time at which sliding begins.
(ii) Calculate the distance travelled by each block during the 5s interval.
(iii) Hence, obtain the ratio of the distances moved by the two blocks and comment briefly on the result.