Date : Name: Problem Set - Motion Near the Earth's Surface Provide 'elegant' solutions for the following problems. 1/ - A man pushes a 25 kg lawnmower along his front lawn. The force that he applies to the handle has a magnitude of 120 N. The handle is set at an angle of 370 above the horizontal. There is an average frictional force of 64 N acting on the lawnmower. Find a) the acceleration of the lawn mower. b ) the coefficient of kinetic friction. 2/ - A 15 kg mass slides down a ramp which is inclined at an angle of 370. If the coefficient of kinetic friction is 0.40, find the acceleration of the mass. 3/ - In the diagram shown to the right, a force of 150 N 150 N is applied at 270 above the horizontal on a block with a mass of 35 kg. The block is 270 35 Kg 10 connected to another block of mass 5.0 kg by means of a string passing over a pulley. The coefficient of kinetic friction between the 35 kg mass and the surface is 0.18. 5.0 kg Find a ) the acceleration of the system b ) the tension in the string 4/ - A 4.0 kg mass is connected to an unknown mass by a string that passes over a frictionless pulley, as shown below. The coefficient of kinetic friction 4.0 kg between the incline and the 4.0 kg mass is 0.40 Once released, the unknown mass accelerates m downward at 5.9 m/s2. 300 Find a ) the tension in the string b ) the unknown mass 5/ - A crate, which slides up a smooth plane inclined F at an angle O with the horizontal, is pushed by a m force F which makes an angle o with the inclined plane as shown in the diagram. Express both the normal force FN exerted by the plane, and the crate's acceleration a as functions of F, m, 0, o and g. e 6/ - Mr Berthiaume left his iPad on the desk at the front of the room. Mr Heath gives it a quick shove so that it begins to move with an initial velocity of 6.5 m/s. How far from the edge of the table will the iPad land if the coefficient of friction between the table and the iPad is 0.15? (see diagram below left) 7/ - Calvin & Hobbes go for another sleigh ride. They start from rest at point A and proceed to point D along the path ABCD. AB is a constant downhill slope, BC is level, and CD is on a constant uphill slope. The surfaces are completely without friction. Calculate how long their trip from A to D will take. 4.5 m V -+ 0.15 kg edge of table 30. m 30 1.8 m 40. m 60. m 30. m