Im doing Mechanics module 2 at college (the only one!) and while working through an exercise i got stumped by this question. "A motorcycle has a mass of 250kg, and it's rider whose mass is 80kg. The centre of mass of the motorcycle lies on a vertical line midway between its wheels. When the rider is on the motorcycle, his centre of mass is 1m behind the front wheel. Find the vertical reaction forces acting through the front and rear wheels when: (i) the rider is not on the motorcycle. (ii) the rider is on the motorcycle." Then it has a stupid picture of a man on a motobike with the distance 1.4m between the centres of the two wheels (so the centre of mass is as 0.7m) Now i looked in the back of the book after many failed attempts and the answers are: (i) 1225N for front wheel, 1225N for rear wheel (ii) 1449N for front wheel, 1785N for real wheel. i cant get those answers!! EDIT take gravity as 9.8 instead of 10.