ok, i need some serious help with newtons second law. like i kind of understand it, but adding things like friction are giving me real problems. does anyone have any good resources or tips on how to understand/comprehend this? and i have a prolem: a man pushes a 15 kg lawnmower at constant speed with a force of 90 N directed along the handle, which is at an angle of 30 degrees to the horizontal. calucalte: (a) the horizontal frictional force on the mower, and (b) the normal force on the mower. well i know the acceleration is zero, but dont you need the kinetic friction to find the frictional force?