SPH3U Mid-Course Assignment (2 hours) (40 Questions) 18. A store clerk pushes a parcel along a counter with a force of 7.6 N[W]. The parcel has a mass of 2.5 8 marks kg. The kinetic friction acting on the parcel is 6.5 N[E]. (a) Draw a FBD of the parcel as it is being pushed. Be sure to label your forces appropriately and to include values. (b) Calculate the net force acting on the parcel. (c) Calculate the acceleration of the parcel. (d) Determine the coefficient of kinetic friction between the parcel and the counter. 19. The force of gravitational attraction between two objects is Fo. By what factor (ie 2x, 1/2x, ...) does 1 mark Fo change if the following occur: (a) The mass of one of the objects is doubled? (b) The distance between their centres is tripled? (c) The mass of both objects are halved? (d) The distance between their centres is halved? (e) Both (a) and (b) occur. 1 mark 20. An experimenter uses a bathroom scale to measure his weight while riding in an elevator. How will the reading on the bathroom scale compare to the normal reading for the following sequence of motion: - elevator starts to ascend - elevator ascends at a constant velocity - elevator stops (a) lighter, lighter, heavier (b) heavier, heavier, lighter (c) lighter, normal, heavier (d) heavier, normal, lighter 21. Max exerts a constant force of 1.5 N to pull a 2.0 kg object at constant velocity along a level 2 marks surface on the moon (g = 1.6 N/kg [down]). What is the coefficient of kinetic friction for this situation? 22. A constant force of 36 N is applied to a 20 kg mass (X) that is in contact with a 4.0 kg mass (Y) on a frictionless surface. What is the magnitude of the force exerted by mass X on mass Y? 2 marks X Y 1 mark 23. Acceleration is always in the direction of the: (a) net force (b) initial velocity c) final velocity(d) displacement 2 marks 24. A net force of 58.0 N[W] is applied to a ball of mass 4.50 x 102 g. Calculate the ball's acceleration