1) A 200N crate rests on an ramp; the maximum angle just before it slips is 25 degrees with the horizontal. What is the coefficient of static friction between crate and ramp surfaces? 2) A 150N sled is pulled up a 28 degree slope at a constant speed by a force of 100 N. What is the coefficient of kinetic friction between sled and slope? 3) A woman at an airport is towing her 20kg suitcase at constant speed by pulling on a strap at an angle above the horizontal. She pulls on the strap with a 35N force, and the friction force on the suitcase is 20N. Draw a free body diagram of the suitcase. (A) What angle does the strap make with the horizontal? (b) What normal force does the ground exert on the suitcase? 4) A 2000kg sailboat experiences an eastward force of 3000N by the ocean tide and a wind force against its sails with magnitude of 6000N directed toward the northwest (45 degrees N of W). What is the direction of the resultant acceleration?