EXAM 3                 December 1, 1995                PHYS 207H
	                                                                               
	      If you need a constant not given here or do not understand a             
	problem, please ask me about it.  Remember to include diagrams and             
	explain your reasoning.  No notes, books, etc. may be used. 
	    
	                2            2                                    -31
	   g = 9.8 m/sec  = 32 ft/sec .   Mass of the electron = 9.11 x 10   kg
	
	                                                 6             
	                  Radius of the earth = 6.38 x 10  m          
	 
	                                                        2    2
	       Moment of inertia of a sphere about a diameter = - M R
	                                                        5 
	
	  1. (10 points)  Write down the equations or general principles                
	
	generally used to solve problems involving  
	
	  (a).  collisions.  
	
	  (b).  equilibrium.   
	
	
	  The remaining problems are worth 30 points each.
	
	
	  2.  Wistful Willie is skating along on very smooth ice at a speed
	
	V  , daydreaming of nothing in particular, when he collides head-on
	 w
	with Dennis the Menace, who is moving in the opposite direction at a
	
	speed V  .  Willie's and Dennis's masses are known.  After the collision,
	       d
	Willie and Dennis stick together.  Find the common speed of the boys
	
	after the collision.
	
	  3.  A car of mass  m  is parked on a slope which is at an angle 
	theta  with respect to the horizontal.  The center of mass of the
	car is halfway between the front and rear wheels and is a distance 
	h  above the ground.  The wheels are a distance  d  apart.  Find the
	normal force exerted by the road on the front wheels.  Is the normal
	force on the rear wheels larger or smaller than that on the front
	wheels?  
	
	  4.  A good but foolhardy skier, having learned his lesson on
	Halfdome, wants to shuss down a somewhat smaller dome-shaped
	mountain.  However, he wants to test the safety of the run, so he
	rolls a ball of radius  r  down the mountain first.  If  R  is the
	radius of the dome, how far down the mountain does the ball get
	before leaving the ground, assuming it rolls without slipping the
	entire way?  
	     Would the skier leave the mountain at the same point, a higher
	point, or a lower point than the ball?