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Create your free account or Sign in to continue. See Subscription Options. Fall Flash Sale. Key concepts Physics Kinetic energy Potential energy Conservation of energy Newton's laws of motion Introduction Turn a pile of trash into a toy car—and watch it go! Materials Plastic bottle Four plastic bottle caps Wooden skewer Two straws Balloon Tape Scissors or sharp knife Have an adult use or supervise your use of this tool.
An adult helper Preparation Cut one of the straws in half. Tape both pieces of the straw to one side of the water bottle.
Cut the wooden skewer in half and push each piece through one of the straws. These will form your axles. Have an adult help. Press each bottle cap onto the ends of the wooden skewers.
These will form your wheels. Procedure Put your car down on a flat surface and give it a good push. Make sure the car rolls easily and coasts for a bit before stopping. In the aviation world, hot air balloons are an incredibly safe form of flight, and they have become increasingly safe over time.
Accidents are uncommon, and fatalities are even rarer. Between and June of , only 21 hot air ballooning fatalities were reported in the United States. How fast is a hot air balloon? The fastest a hot air balloon has ever traveled is miles per hour.
A huge sack of hot air attached to a tiny gondola achieved a ground speed of miles per hour. How much wind is too much for hot air balloon? To ensure a safe flight, hot air balloons should never fly in wind above 10 mph. In most cases, a balloon won't even take off in winds exceeding 12 mph. Ideally, a hot air balloon would like to fly in mph winds. High winds can seriously damage a balloon and injure passengers.
Can hot air balloons fly at night? It is possible for balloons to fly at any time during daylight hours on a calm winter's day. Put one end of each wooden skewer through your wheel. If the wheel is loose on the skewer use modeling clay to hold in place. Slide the skewers through the straw and attach the rest of the wheels to the skewer.
Now you should have a rolling chassis! Assemble the Motor: a. Insert the nozzle part way into the balloon. Use a rubber band and secure the nozzle to the balloon. Insert the nozzle through the slit on the top of your water bottle.
Make sure about an inch of the nozzle is sticking out of the mouth of the bottle. Now your team is ready to test!
Make your way over to the test track. Line the Rocket car up on the starting line and when the track is clear release the balloon. You can start by mounting the wheels on this body. The air in the balloon is gas under pressure. The air pushes against the balloon, causing it to expand, but the balloon is also pushing back on the air. The pressure of the balloon pushes the air right out through the nozzle, which creates thrust that propels the car forward. Keep track of how long the rocket car travels and how far it goes.
Try it several times, then try changing the design to see if you can get it to go farther or faster. How will it work if you only use three straws for the nozzle? What if you use a bigger or smaller balloon?
Does the car go farther on linoleum or the sidewalk? Why do you think this might be? Will the car go farther if you start it at the top of a ramp? Decorate your car and have races with siblings or friends. Try to figure out why one car goes faster or farther than another, and keep experimenting to make your design better! The Alka-Seltzer reacts with water to produce carbon dioxide.
When enough carbon dioxide is produced to create pressure on the inside of the canister, it will force the lid to pop off so the gas can escape. As the gas escapes the rocket is propelled upward.
Try to measure how high your rocket goes compared to a nearby fence or a tree. Try it several times; do you get the same results each time? Does the rocket go higher if you add more or less water? Why do you think this is?
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