PHYSICS 1403, QUIZ 4
Chapter 6
March 10, 2004
Partial credit will be LIBERAL, provided that you show your work!
USE BACK IF NEEDED!
Name: ______________________ Social Security Number ______________________
1.
(10 points) CONCEPTUAL QUESTIONS!! Using complete, grammatically correct, English
sentences, answer the following questions: (You may supplement the sentences with equations if you
explain what each symbol in the equations means).
a. State the Work-Energy Principle.
b.
2.
State the Principle of Conservation of Mechanical Energy. (Note: This is NOT the same as the
Law of Conservation of Energy, which states that energy can neither be created nor destroyed but
can only be transformed from one form to another!).
(20 points) See figure. Note: This problem can be solved either using the Newton’s 2 nd
Law (Force) methods of Ch. 4 or the Energy Methods of Ch. 6. This is a quiz over Ch.
6, so you are required to USE ENERGY METHODS TO SOLVE THIS PROBLEM!
You will receive no credit for using the methods of Ch. 4 to solve this problem! You
don’t need to resolve forces into components to solve this problem!! The angle  is not
needed to solve this problem! A block of mass m = 150 kg, initially at rest, slides down
a frictionless inclined plane. The initial height is h = 3.5 m above the floor.
a. Compute (find a numerical value for) the gravitational potential energy of the block at its
initial position. How much work must be done by gravity to move the block down the
incline?
b.
Compute (find a numerical value for) the kinetic energy of the block at the bottom of the
incline. Compute its speed at the bottom of the incline.
c.
Compute (find numerical values for) the potential energy and height y of the block when its
speed is v = 6.0 m/s.