Lafayette College
Department of Physics
February 6, 2009
Physics 131 LevelIIHomework Set Section 1
Youmay discuss these problems with one or twoother students (or with your instructor), but
your final solutions should be written out by you alone. Under no circumstances should you see
another student’swritten solutions. If you have discussed these problems with anyone you must
acknowledge the collaboration at the beginning of the corresponding problem. Homework is due
in my office by 3:30 PM on the due date and solutions will then be made available on the course
web site. No homework will be accepted after this time.
Youare expected to carefully explain how, starting from basic principles, you have arrivedat
your answers. Please do not use paper with edges frayed from being ripped out of a spiral bound
notebook. If the papers are illegible or disorganized, we reservethe right to return these papers
without being graded. Unless instructed otherwise, all answers should be correct to 3 or 4 sig.
figs.
Assignment Week 2: Due Friday,February 6, 2008
Problem 1: A bolt comes loose from the bottom of the shuttle on lift-offatthe time that the
shuttle is moving upward at a speed of 94.0 m/s. The bolt hits the launch pad in 18 5.0 seconds.
A) Howhigh up was the shuttle when the bolt came loose?
B) What was the speed of the bolt when it hit the launch pad?
C) What was the acceleration of the shuttle (assumed constant) from launch to the time
the bolt came loose?
Problem 2: A stone is dropped into a deep water well and a splash is heard after 7. 75sec-
onds. Howdeep is the well? Be very careful and think about the physics of this problem before
you write anyequations. I want the answer to 4sig. figs and a position vs time diagram that il-
lustrates your answer!
Problem 3: A passenger train is behind a freight train, both on the same set of tracks and
moving in the same direction. The freight train is moving at a constant speed of 25.0 m/s and
maintains that speed. The passenger train is originally moving at 35.0 m/s when the engineer of
the passenger train spots the freight train and applies the brakes. At the time the brakes are ap-
plied, the separation between the trains is 325. 0 meters, and the application of the brakes causes
the passenger train to have a constant acceleration in the direction opposite to the train’svelocity.
A) If there is to be no collision, what must the minimum value of the magnitude of the ac-
celeration of the passenger train?
