INFORMATION FOR THE FINAL EXAM
The final exam will be given in this classroom, from 8:30-10:30 on Friday, 13 May 2005. The exam will be comprehensive and cover all
material covered in the course, including Chs 1-8 and 17 of the text, along with handouts and the information relating to labs and in
class activities.
You can expect the format of the final to follow closely the format of the hour exams, with questions integrating material from the
first and second halves of the semester as possible. For instance, I might ask questions of the sort:
Consider an object of mass 10 kg on a flat surface where the coefficient of friction is 0.5. If a force of 60 N is applied to push
the mass, answer the following:
a) What is the net force on the object?
b) What is the acceleration of the object?
c) How far will the object travel in 5 secs?
d) What will be its speed at the end of 5 secs?
This question incorporates concepts of motion and force, ideas we studied throughout the semester.
I will likely ask you to describe how you might construct experiments to demonstrate important concepts in the course, such as
describing how you would construct an experiment (and the materials you would need) to demonstrate how an inclined plane acts as a
machine, or how to measure the acceleration of an object rolling down an inclined plane
I will hold dedicated office hours for the final exam in my office in LSB 430 at the following days/times:
Monday, 9 May 11:30-1:30
Tuesday, 10 May 11:30-1:30
Wednesday, 11 May 1:30-4:00
Thursday, 12 May 10:30-1:00
You may also call at 8-8352 or email me at dslavsk@luc.edu
Answer to questions above:
a) The frictional force will be the coefficient of friction x the force pushing the surfaces together; in this case, that is the weight
of the object. If its mass is 10 kg, then its weight is W = mg = 10 kg x 10 m/s/s = 100 N. Then, the frictional force becomes 1/2W =
50 N. Now, if the pushing force is 60N, and the opposing frictional force is 50 N, the net force on the object is 10 N.
b) Newton's second law states the sum of Forces = ma. Here, the net force is 10 N, the mass is 10 kg, and we can easily calculate
that the
acceleration is 1 m/s/s.
c) The distance an object travels if it is accelerating is given by d=1/2 a t2; we know that a = 1 m/s/s and t = 5 sec, so
that d = 1/2 (1)(5)2 = 12.5 m.
d) Remembering that a = (Delta v) /t = (v f - vi)/t = (vf - 0)/5s allows us to write that:
vf = a x t = 1 m/s/s x 5 s = 5 m/s
David B. Slavsky
Loyola University Chicago
Cudahy Science Hall, Rm. 404
1032 W. Sheridan Rd.,
Chicago, IL 60660
Phone: 773-508-8352
E-mail: dslavsk@luc.edu
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