Agriculture
Where Have All the Bees Gone?
Earth-Friendly Fabrics
Flush-Free Fertilizer
Amphibians
Toads
Salamanders and Newts
Bullfrogs
Animals
Elephant Mimics
Insect Stowaways
Who's Knocking?
Behavior
Copycat Monkeys
Fighting fat with fat
Nice Chimps
Birds
Waterfowl
Birds We Eat
Pigeons
Chemistry and Materials
Music of the Future
Boosting Fuel Cells
A New Basketball Gets Slick
Computers
The science of disappearing
Batteries built by Viruses
Galaxies far, far, far away
Dinosaurs and Fossils
Dino-Dining Dinosaurs
Dino-bite!
Supersight for a Dino King
E Learning Jamaica
2014 GSAT Results for Jamaican Kids
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Results of GSAT are in schools this week
Earth
Giving Sharks Safe Homes
Island of Hope
Vitamin D-licious Mushrooms
Environment
Shrimpy Invaders
City Trees Beat Country Trees
The Birds are Falling
Finding the Past
Settling the Americas
Ancient Cave Behavior
Chicken of the Sea
Fish
A Grim Future for Some Killer Whales
Manta Rays
Tiger Sharks
Food and Nutrition
Chew for Health
The mercury in that tuna
A Taste for Cheese
GSAT English Rules
Capitalization Rules
Whoever vs. Whomever
Pronouns
GSAT Exam Preparation Jamaica
Tarrant High overcoming the odds
GSAT Scholarship
42,000 students will sit for the GSAT Exam in two weeks
GSAT Exams Jamaica Scholarships
GSAT Scholarship
42,000 students will sit for the GSAT Exam in two weeks
Results of GSAT are in schools this week
GSAT Mathematics
It's a Math World for Animals
How to Slice a Cake Fairly
How a Venus Flytrap Snaps Shut
Human Body
Smiles Turn Away Colds
Workouts: Does Stretching Help?
Football Scrapes and Nasty Infections
Invertebrates
Leeches
Fleas
Daddy Long Legs
Mammals
Pitbulls
Marmots
Asiatic Bears
Parents
What Not to Say to Emerging Readers
How children learn
The Surprising Meaning and Benefits of Nursery Rhymes
Physics
Black Hole Journey
Invisibility Ring
Speedy stars
Plants
The algae invasion
Getting the dirt on carbon
Stalking Plants by Scent
Reptiles
Crocodilians
Chameleons
Geckos
Space and Astronomy
Wrong-way planets do gymnastics
A Planet's Slim-Fast Plan
Intruder Alert: Sweeping Space for Dust
Technology and Engineering
Space Umbrellas to Shield Earth
Supersuits for Superheroes
A Satellite of Your Own
The Parts of Speech
Pronouns
Adjectives and Adverbs
Countable and Uncountable Nouns
Transportation
Morphing a Wing to Save Fuel
Seen on the Science Fair Scene
Reach for the Sky
Weather
Warmest Year on Record
Antarctica warms, which threatens penguins
Catching Some Rays
Add your Article

Road Bumps

If you've ever been in a car that's traveling down a dirt road, you know how bumpy the ride can be. Dirt roads often develop ridges—and until recently, no one knew why. These bumps are usually several inches high, and they occur every foot or so. Workers can use bulldozers to flatten the dirt, but the ridges reappear soon after cars hit the road again. Scientists have attempted to explain why ridges form, but their theories have been very complex. As a result, engineers haven't been able to put the theories to the test or to design bumpfree dirt roads. Recently, researchers at the University of Toronto and their colleagues at the University of Cambridge in England attempted to come up with a simple explanation of why the ridges form. They began by building a turntable—a round, flat surface that rotates, somewhat like the spinning surfaces sometimes found on large restaurant tables. To make a model dirt road, the scientists covered the turntable with grains of dirt and sand. They placed a rubber wheel over the surface so that it rolled over the dirt as the turntable rotated. In repeated tests, the scientists varied conditions in every way that they could think of. They used grains of different sizes and mixtures. Sometimes they packed down the dirt. Other times, they scattered the grains loosely on the surface. The researchers also tested wheels of different sizes and weights. They even used a type of wheel that didn't spin. And they rotated the turntable at a variety of speeds. Depending on conditions, the distance between ridges varied. But the ripplelike ridges almost always formed, regardless of what combination of factors the scientists used. To better understand what was going on, the team created a computer simulation that showed how individual grains of sand move as a tire drives over them. The computer program showed that dirt surfaces, even those that look flat, actually have tiny bumps. As a wheel rolls over these little bumps, it pushes the dirt forward a small amount. This nudge makes the bump get slightly bigger. When the wheel then passes over the bump, it pushes dirt down into the next bump. After a hundred or so repetitions—not unusual for a well-used road—the bumps turn into a pattern of deep ridges. What's the solution? The only way to avoid a bumpy ride, the researchers found, was to slow way down. If all cars travel at a poky 5 miles per hour or less, a dirt road will remain flat.—Emily Sohn

Road Bumps
Road Bumps








Designed and Powered by HBJamaica.com™