Category Archives: Sick Science! Videos

How to Avoid Labor Day and Summer Barbecue Fires

Barbecue grills are a big part of summer and especially the end of summer over Labor Day weekend. With a barbecue or charcoal grill, food is cooked over a flame. Where there is fire, there is an inherent danger. In this week’s video from 9News, Steve explains how a common mistake can have tragic results.

Occasionally during the summer barbecue, lighter fluid erupts in the hands of the chef. This happens when the fuel is sprayed onto a barbecue or charcoal fire, the flames ignite the liquid and travel up to the bottle. As the squeeze bottle is released, the flame is sucked inside, along with oxygen. The chef thinks they are ok, because the flame is no longer visible, but the flame, along with the fuel and oxygen create the perfect environment and explode.

Firefighters warn of this danger using lighter fluid and of the dangers with flammable gases. Some are lighter than air and are flammable, like methane or hydrogen. Depending on conditions, these gases can ignite in a fire. A popular demonstration used by firefighters is the Methane Mamba.

Steve uses a classroom demonstration with a Pringles can, hydrogen gas and a lighter. When the flame burns down into the can, an explosion is the release of perfect conditions for a release of energy inside the can. This is exactly what happens when lighter fluid explodes during a summer cookout.

When cooking outside, please be extremely careful when using lighter fluid around an open flame. If the flame is sucked into the bottle, get away from it quickly. The fire did not go out, and is instead burning the fuel inside the bottle.

Just Add Water – A Summer Exhibit at the Denver Children's Museum

The Denver Children’s Museum offers fun activities right outside their doors this summer in an exhibit called Just Add Water.


Kids will get wet, drip and splash in this hands-on exhibit. It’s learning through play and there are even a few water geysers throw in.

This is a summer-only event and only goes for a little while longer before closing for the season. But don’t worry, Just Add Water will be back in the summer of 2013.

 

 

Take the Olympic Challenge – Swing Water Over Your Head Without Spilling It

The Olympics are winding down and you all must be tired of sitting on your couch day after day watching athletes do the impossible. Now, it’s your turn to get up and start swinging.

This demonstration will require some thin rope or strong string, water and plastic food storage containers.

Drill holes in the four corners of the container and tie the string in each hole. Tie all four strings together at the top to make a water swing. Then fill the container with water.

Make sure you are outside or in an open space and away from brothers, sisters and the dog when you start swinging. Don’t do it around the family China either or over the brand new carpet.

Swing the water container around in a circle and over your head. Just don’t stop!

The water will stay inside the container and not spill out everywhere as long as you keep it moving in one direction. Stopping too fast or changing directions suddenly may cause the water to spill out everywhere.

If you are up for a challenge, try a water swing in each hand.

Why doesn’t the water spill out when the container is upside down? Centripetal force meaning “center seeking” keeps the water from going everywhere.

Centripetal force is a force that is always directed toward the center of the circle. According to Newton’s First Law of Motion, objects in motion tend to remain in motion unless acted upon by an external force. The water continues to move along a tangent to the circle and does not fall out of the container.

 

The Office Olympics – The Science of Office Chair Spinning

There is science behind the tucks, spins, jumps and throws in the Olympics.

Power walking is now an Olympic event, so why not spinning? I’m already dizzy and we’ve barely begun.

If you need to bring more Olympics in your life, pull out the office chair, start doing a little science and compete in the Office Olympics.

There is a science to spinning the fastest in an office chair spin-off. To win the gold, you must understand a little about inertia, mass and velocity.

Hold your arms out while spinning on the office chair and you will keep your balance, but pull them into your body, and you’ll spin faster. By bringing the arms in, you change your angular velocity.

Ready for a few scientific definitions?

In simple terms, inertia is the tendency for an object to resist a change in its motion.

Mass is how much stuff is in an object. It gets confused with weight – but weight is the force of gravity on the object. An object like a rock may weigh differently on the earth than it does on the moon, but it’s mass is the same no matter where it is found. Mass is also a numerical measurement of its inertia.

Velocity is the rate at which an object changes its position, or its speed. Angular velocity is speed in a circular motion. Linear velocity is speed in a straight line.

Change your mass by holding a few cans of food or weights. Now spin with your arms out and then bring them back in.

The mass can also affect angular velocity. The mass held out at arms’ length will slow down an object’s angular velocity, but bring the mass into the center of gravity, and that object will spin even faster.

Are you ready to go for the gold? Go grab an office chair, some co-workers and a few lightweights. Just don’t share your science secret until after the competition.

Save Electricity, Skip the Campfire, Go Old School and Cook on a Solar Oven

The hot, dry weather in Colorado has forced officials to enforce fire bans across the state. That means no campfires, no s’mores, no nuttin’. Or is it possible to harness the power of the sun using a technique that is used by Girl and Boy Scouts and other ingenious campers who want to spare the lighter fluid, charcoal or wood to cook a meal?

To make a solar oven, start by going out for pizza and keeping the cardboard box. Cut a flap inside the lid of the box so you have a lid inside a lid.

Cover the inside box bottom with aluminum foil and then place a piece of black paper on top. Cover the inside of the box lid with clear plastic wrap and the inside of the lid you cut out in step one with more aluminum foil.

It’s time to start cooking those s’mores. Place a few graham crackers on the black paper and layer with chocolate and marshmallows. Leave it out in the sun for about 10 minutes, more or less depending on the strength of the sun. BAM! S’mores for the family without a spark or fire.

The aluminum foil reflects the sunlight and harnesses the heat on the marshmallows and chocolate. The black paper absorbs that heat and increases the heat inside the box. The plastic also holds in the heat and protects the food from critters or dirt while cooking the food.

Here’s more on the science of the sun, sunscreen and step by step instructions on how to make our solar oven from The Spangler Effect -