Web Activities
UNIT 1 - FORCES AND MOTION: DYNAMICS
Chapter 2 - Dynamics
2.2 Newton's Laws of Motion
Practice (p. 83)
- Mining operations in outer space will require unique innovations
if they are carried out where there is a very low force of gravity,
such as on asteroids or the moons of various planets. One plan is
to develop a device that will push particles with the same constant
force, separating them according to the accelerations they achieve.
Research "mining methods in zero-g" to learn more about this
application of Newton's second law. Describe what you discover.
Riches
in the Rubble
An article that discusses the potential resources available on other
planets and on natural satellites and moons. There is a discussion of
different ways that mining could take place in space.
Particle
Separation by Density
This link contains the abstract of a research paper on ways that this
mining can happen out of the University of Charleston.
Section 2.2 Questions (p. 87)
- An astronaut in the International Space Station obtains a measurement
of personal body mass from an "inertial device," capable of
exerting a measured force. The display on the device shows that a
net force of 87 N [fwd] gives the astronaut an acceleration of 1.5
m/s2 [fwd] from rest for 1.2 s.
- Why is the astronaut unable to measure personal body mass on
an ordinary scale, such as a bathroom scale?
- What is the mass of the astronaut?
- How far did the astronaut move during the 1.2-s time interval?
- Research how an inertial device works. Write a brief description
of what you discover.
NASA:
Measuring Inertial Mass
This 6-page site has a neat activity to help you understand how to measure
inertial mass.
Measuring
Inertial Mass in Space
This site has good info on measuring inertial mass in space, including
an illustration of the inertial balance used on Skylab.
2.4 Exploring Frictional Forces
Section 2.4 Questions (p. 107)
- In 1896, Carl E. Johansson of Sweden produced the first gauge
blocks (also called "Jo blocks" in his honour) for quality
control in manufacturing. Since the blocks have extremely smooth sides,
the coefficient of static friction is high. The blocks thus stick
together upon contact. (You have likely noticed a similar strong bonding
when microscope slides stick together.) Research the topic of gauge
blocks, describing their properties and uses.
OPUS
Metrology
A company that produces and distributes gauge blocks. Look at the company
profile to discover how their product is used and investigate the different
types of available gauge blocks.
The
Origins of Gauge Blocks
The history and initial uses of gauge blocks are described here.
- What are the meanings of the terms "slice" and "hook"
in golf? What causes slices and hooks? What can you do to prevent
them?
The
Physics of Golf
A four-page Web site that describes, in great detail, the physics of
a spinning golf ball.
Sports
Illustrated
This site gives discussions of hooks and slices. There are animated
GIFs that show aerodynamic effects.
Mr
Golf, The "Slice" Problem
Discusses the slice with respect to Bernoulli's effect.
- Running-shoe designs have changed with advances in technology.
Research how the soles of running shoes have evolved, writing a few
sentences on your findings.
New
Balance
This site has the latest technologies used in the design and production
of running shoes.
The
History of Shoes
Specifically look at the sneakers section.
Charlie's
Sneaker Page
Frequently asked questions and a glossary of running shoes.
- The near-frictionless carbon (NFR) listed in Table 1 is a new,
ultra-hard carbon film with a coefficient of kinetic friction of only
about 0.001 in an environment of nitrogen or argon. Although the coefficient
is greater in an ordinary environment of air, the friction remains
low enough to give this amazing material many applications. Research
the advantages and uses of NFC, and write a report on what you discover.
Argonne
Technology: Near Frictionless Carbon Coating
Nano-sized
Bearings, Switches and Probes crafted for Micromachines
There's
Something Slicker than Teflon?
