Monday, March 31, 2014

Thank You Waco Fire Department for Helping Young Scientists Design and Compete

Can you design a device that will protect an egg from a 20 foot fall?
What about a 30 foot fall?
What about a 60 foot fall????  

Rapoport 4th Grade Science Club members were up for the challenge designing and competing to see whose egg would SURVIVE and whose would SPLAT!

In the classroom, students discussed basic physics of on how to design for impact.  Two primary methods were employed in their designs: (1) slow the rate of fall and (2) cushion the egg at impact.

Each student was given basic kit components then allowed to choose a few additional items to include in their own design.  Eggs were placed into each device and then........ they were put to the test!  With the help of the Waco Fire Department and one of their ladder trucks, students were able to test their device.

Eight of the designs were successful at the sixty foot height!  Wow that is REALLY Impressive!
(An object dropped from 60 feet is traveling at 62 miles per hour when it reaches the ground.) 
Students used various design strategies to slow the fall and protect the eggs ensuring they would SURVIVE and not SPLAT.

Congratulations to all of our students for some fantastic designs and thanks to the Waco Fire Department for your encouragement to some future scientists, engineers, doctors, and fire fighters!

Sunday, March 23, 2014

Why is a Dog's Sense of Smell So Powerful?

A dog relies on her sense of smell to interpret her world, in much the same way as people depend on their sight.   How can a dog’s sense of smell be so keen?  First, they have many more scent-detecting cells than humans.  Take a look at this comparison:

Species                                     Number of Scent Receptors
Humans                                             5 million
Dachshund                                     125 million
Fox Terrier                                     147 million
Beagle                                            225 million
German Shepherd                          225 million
Bloodhound                                   300 million

A dog's brain is also specialized for identifying scents. The percentage of the dog's brain that is devoted to analyzing smells is actually 40 times larger than that of a human! It's been estimated that dogs can identify smells somewhere between 1,000 to 10,000 times better than nasally challenged humans can.

Dogs are incredible!

Wednesday, March 19, 2014

Think Like a Scientist and EARN A REWARD !

Pesticides are designed to kill insects, mites or nematodes. But, they can also poison other critters, including bees or even people.  Kids are exposed to a wide variety of pesticides every day. Shoes track these chemicals into our homes. The wind spreads them beyond the field or garden. Some bug or rodent killers are even designed for use in homes. And traces of pesticides may be on our foods.  Even low levels of pesticides can cause behavioral problems, trouble concentrating or even cancer, notes the American Academy of Pediatrics (AAP).

We can take steps to reduce pesticide exposure. One way is to eat organic foods. Another is to take a natural approach to pest control.  For instance, gardeners or farmers may release ladybugs or other natural predators onto their plants. There, the good bugs munch on the pests. Or growers can plant things that attract birds.  The birds will patrol a yard or field snacking on caterpillars, grasshoppers and other animals that may pose a threat to plants. 

Fewer pesticides means a safer environment for people, pets and welcomed wildlife — including bees.
This post based on information on the StudentScience webpage.  Click here for more info: Student Science Webpage

Think Like a Scientist and Earn a Reward!
Ask your parents if you have any pesticides in your home and ask them to help you answer the following questions.  (Do not handle any pesticides without adult supervision.)
  • What is the name of the pesticide?
  • Does the front of the can or bottle have a warning label?  If so, what does it say?
  • Where does your family use this pesticide?
  • Has the person who uses the pesticide read the warnings (so they can use it safely)?
  • If you did not use the pesticide to kill bugs, what would happen?
  • What are three other methods you might use to control the bugs (instead of using pesticide)?

Write your answers on a sheet of paper and give to Mrs D by Friday, March 28th to EARN A REWARD!  You can also email your answers to:

Sunday, March 2, 2014

How Do You Win Olympic Gold? Talent, Hard Work, and SCIENCE!

Dr. Dan Durben, Black Hills State University associate professor of physics, and member of the 1988 U.S. Olympic rifle team, recently spoke about science and Olympic gold medal winners.  Durben said. “Elite athletes have a whole team behind them. One critical area is sports science.  We study the actual physics behind what the athletes are doing… to get an understanding of what is happening.”

Sometimes You Think You Know the Answer.....
His first study involved determining why male figure skaters could do triple jumps and women could not. Coaches and athletes concluded that figure skaters use their legs; therefore, women must not have the leg strength that men do. They put the female figure skaters on a lower body program, but results did not change.

But You Really Need Science to Solve the Problem....
When the sport science team looked at the problem, they analyzed the physics to see what was going on when the figure skaters jumped. To generate a lot of angular momentum, figure skaters need to have their arms spread wide which in turn increases their moment of inertia. However, the tighter a skater is, the faster they can rotate so during a spin they want to pull their arms in. When spinning fast, the arms tend to fly back out, Durben said.
“The women didn’t have the upper body strength of the men to be able to go into a jump but snap those arms in fast enough to get around three times.” This research resulted in coaches putting their female skaters on upper body programs enabling them to complete triple jumps, Durben said.
This blogpost contains info from an article in the Black Hills Pioneer Newspaper, 2014.Thanks very much BHP.

To get a better understanding of how this works, click on the video below! In the first spin, the skater holds her arms out and spins slowly.  In the second spin, she must pull her arms in tight - this makes her spin much faster!