EXAM 1                September 30, 1994               PHYS 207                      
	                                                                               
	      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.  Each
	problem is worth 25 points.
	                                    2            2
	                       g = 9.8 m/sec  = 32 ft/sec                       
	
	                                                     -31                                       
	                The mass of the electron is 9.11 x 10    kg                                    
	
	                                                      6                                          
	                  The radius of the earth is 6.38 x 10  m                                        
	
	      1. a.  Sketch a single v-versus-t curve in which there are
	(labelled) points or segments where
	  (1) the acceleration is zero and constant while the velocity is
	not zero,
	  (2) the acceleration is zero but not constant,
	  (3) the velocity and acceleration are both positive,
	  (4) the velocity is positive and the acceleration is negative,
	  (5) the velocity is zero but the acceleration is not.
	
	         State and explain how to remember (not necessarily derive):   
	
	         b.  The relations for the position and velocity of a
	particle as a function of time for motion in one dimension with
	constant acceleration. 
	
	         c.  The relation giving the magnitude of the acceleration
	for a particle moving at constant speed  v in a circle of radius  R.
	
	         
	      2.  An automobile has wheels of diameter 65 cm.  What is the
	acceleration of a point on the rim of of this wheel when the
	automobile is travelling at a constant speed of 110 km/hr?
	
	
	      3.  (From homework)  A worker on the roof of a house drops
	
	a hammer, which slides down the roof at a constant speed of 4 m/s.
	                             o  
	The roof makes an angle of 30  with the horizontal, and its lowest
	
	point is 10 m from the ground.  What is the horizontal distance
	
	travelled by the hammer between the point that it leaves the roof of
	
	the house and the point where it hits the ground?
	
	  
	    4.  An elevator ascends from the ground at uniform speed.  At
	
	time T  a child drops a marble through a hole in the floor .  The
	      1
	marble falls with uniform acceleration  g  and hits the ground  T
	                                                                 2
	seconds later.  Find the height of the elevator at time  T .
	                                                          1