Physics I [Phys 161]                        Spring 2005 Assignment #5 Problems For Exam 3, you will be expected to do problems of difficulty similar to those below without reference to the text or to any notes.  Make sure that you can do this before you move on to the next assignment! Graded Homework Problems Do Assignments 5A and 5B at www.masteringphysics.com . Mandatory Homework Problems [1] Problem 26 on p. 230 of Knight. [2] Problem 30 on p. 230 of Knight. [3] Problem 34 on p. 231 of Knight. [4] Problem 44 on p. 232 of Knight. [5] Suppose that a pitched baseball strikes another object.  Is it possible for the baseball to deliver more momentum to the object that it strikes than it had initially?  Explain. [6] If two objects collide and one is initially at rest, is it possible for both to be at rest after the collision?  Is it possible for one to be at rest after the collision?  Explain. [7] A bomb explodes.  Is its linear momentum conserved?  Explain. [8] Is conservation of momentum violated when you take a step?  Explain. [9] A friend claims that, as long as he has his seatbelt on, he can hold on to a 12.0 kg. child in a 60.0 mi/h head-on collision with a brick wall in which the car passenger compartment comes to a stop in 0.050 seconds.  Determine the magnitude of the force that he will have to exert to hold on to the child, and show that he will fail.    [10] A railroad car of mass 2.50 x 104 kg is moving with a speed of 4.00 m/s.  It collides and couples with three other coupled railroad cars, each of the same mass as the single car and moving in the same direction with an initial speed of 2.00 m/s.  What is the speed of the four cars after the collision? [11] A 3.0 kg. steel ball strikes a wall with a speed of 10 m/s.  At impact, its velocity makes an angle of 60° with respect to the wall's surface.  The bounces off with the same speed and angle.  If the ball is in contact with the wall for 0.200 seconds, what is the average force exerted by the wall on the ball?