1)A gardener pushes a 12 kg lawnmower whose handle is tilted up 37 degrees above horizontal. The lawnmower's coefficient of rolling friction is 0.15. How much power does the gardener have to supply to push the lawnmower at a constant speed of 1.2 m/s? not really sure where to begin with this one. so any suggestions as to how to start would help. ========================================================= The spring in the figure has a spring constant of 1200 N/m. It is compressed 15.0 cm, then launches a 210 g block. The horizontal surface is frictionless, but the block's coefficient of kinetic friction on the incline is 0.210. What distance d does the block sail through the air? http://s93755476.onlinehome.us/stuff/knight.Figure.11.72.jpg this one seems like it has several parts. i know i could figure out the velocity that the block travels on the flat surface from the spring using like K + U = K + U for initial and final. and using 1/2kx^2 instead. and something simliar for going up the hill. but the part where its in the air is where i get lost.