Homework #5
Due midnight Sunday October 23.
1. Give an example of a sport where the buoyant force is used to reduce drag.
2. The drag force is
F
=
CρA
(
v
2
/
2). Give sports examples that illustrate
the importance of each of the four terms on the righthand side of this
equation (a total of four examples).
3.
Work
(a) Give a sports example of a force that does positive work.
(b) Give a sports example of something that is tiring but does not involve
work.
(c) Give a sports example of a force that does negative work.
(d) Give a sports example where the force and motion are
not
parallel,
so only the parallel component of the force contributes to the work.
4. Examine Table 5.1 of the Lecture #9 lecture notes. (In each case, answer
with a pair of objects from the table.)
(a) What has a larger kinetic energy because it has a larger mass (even
though it is slower)?
(b) What has a larger kinetic energy because it has a larger speed (even
though it is lighter)?
5. Examine Figure 518 in light of the principle of conservation of energy.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Fall '08
 Mcwilliams,R
 Physics, Energy, Force, Potential Energy, Work, larger kinetic energy, sports example

Click to edit the document details