Bad Bounce? How the forces that make inflatable bounce houses fun can also hurt you.
The United States Consumer Product Safety Commission sets safety standards for things people buy. In 2015, it studied bounce house injuries. It estimated that more than 16,000 people visited emergency rooms after getting hurt in bounce houses in 2013 (see Injury Rate, right).
"That number is probably much higher now," says Dr. Gary Smith. He studies injuries at Nationwide Children's Hospital in Columbus, Ohio. "Bounce houses have become more popular every year, so injuries have skyrocketed."
The forces that make bounce houses exciting can also hurt you. But by understanding how they work, you can stay safer when you take the leap.
Most bounce houses are made of a stretchy material called vinyl (VY-nuhl). Air is pumped through them to help them hold their shape.
When you jump onto a bounce house, your feet push down on the stretchy vinyl. As the vinyl snaps back to its original position, it pushes up on your body. That force flings you into the air, explains Becky Thompson. She's a physicist at the American Physical Society in College Park, Maryland.
Soon, the force of gravity pulls you back down. Unfortunately that's when many injuries occur.
Almost half of all bounce house injuries happen when jumpers land in the wrong position, says Smith. If you hit the floor at the wrong angle, you can twist an ankle, sprain a wrist, or break an arm or leg. Stunts like somersaults can result in even more-serious injuries. Landing on your head or neck can damage your spinal cord, which connects your brain to the rest of your body.
Kids also get hurt when they crash into each other. And the bigger the jumper, the greater the force of the impact. Smaller people accelerate, or change speed, more easily. "That means that if a big kid bumps a smaller kid, the smaller kid will go flying," says Thompson.
You can reduce your risks in a bounce house by following a few rules, says Smith. First, don't bounce with too many other people. Everyone should have plenty of space. Jump only with kids of about the same size--no fifth-graders and first-graders at the same time.
Stay aware of people around you to prevent crashes. "And absolutely no somersaults," says Smith. "They cause the most devastating injuries."
Most important, never play in a bounce house without supervision. An adult should be there to enforce the rules--so you can focus on having fun.
READING LEVELS: Lexite 840 / Guided Reading Level R
NEED A LOWER READING LEVEL? To access this article at a lower reading level, go to scholastic.com/superscience.
Design a helmet that could help prevent a head injury when jumping in a bounce house.
Core Idea: PS2.B: Types of interactions
Practice: Designing solutions
Crosscutting Concept: Cause and effect
Reading Informational Text:
1. Refer to details and examples in a text when explaining what the text says.
Science: 3.6C, 4.6D, 5.6D, 6.8B
ELA: 3.9, 4.7, 5.7, 6.7
1 Make observations about how items bounce off a springy surface.
A day in advance, prepare for the introduction activity. You will need several small disposable plastic bowls, one balloon for each bowl, scissors, and packing tape. Cut off the mouth of each balloon just below its widest horizontal diameter. Discard the mouthpiece. Stretch the balloon material over the entire opening of each bowl. Tape the material onto the bowls.
Divide students into groups of three or four. Give each group a balloon-covered bowl and two marbles of different sizes. Have students work together to observe and record what happens when the marbles are dropped on the bouncy surface. Ask:
* What happens when you drop just the smaller marble onto the balloon surface? What about the larger marble?
* What happens when you drop both marbles at the same time? (The marbles collide, and the smaller marble bounces higher than it did alone.)
Record students' observations on the board.
(2) Read the article and respond to prompts about the forces at work in a bounce house.
Read "Bad Bounce?" as a class. Switch readers after each paragraph. After reading the article, allow students to complete the "Stop and Check!" skills sheet available at scholastic.com /superscience.
Show students the video "The Science of Bouncing" available at scholastic.com/superscience. After the video, ask: How is a person bouncing in a bounce house similar to a marble bouncing on the balloon material? How is it different?
(3) Design a protective helmet.
Pass out the skills sheet "Gear Up" (T5). Explain to students that they will work in small groups to design a prototype for a helmet to protect a person's head from injury.
Have each group present their designs and results to the class. Ask: Did all of the designs meet the design criteria?
available at scholastic.com/superscience
Gear Up (T5): Design, build, and test a prototype helmet that could prevent injuries while jumping in a bounce house.
Stop and Check! (online only): Respond to prompts after reading paragraphs from the article.
Bounce Time (online only): Learn more about the forces that cause objects to bounce.
On a Roll (online only): Knock the target ball into the pocket using a rolling cue ball. How many puzzles can you solve?
Caption: As bounce houses have become more popular, the number of injuries in them has increased.
Caption: Injury Rate
About 100,000 Americans visited emergency rooms for bounce house injuries between 2003 and 2013. *
Think: Could you use this graph to predict the number of E.R. visits in i 2018? Why or why not?
In "Bad Bounce?" (pp. 8-9), you read that following simple rules can reduce the risk of being hurt in a bounce house. Imagine you wanted to design a piece of protective gear to help keep people safer. Follow the steps below to design a prototype, or testable model, for a helmet to protect people's heads in a collision.
Observe: Bounce house injuries can happen when two jumpers collide. Helmets can help protect people's heads. The egg yolk inside a hard eggshell is similar to a brain inside a skull.
Define the Problem: How would you design a "helmet" to keep an egg from breaking during a collision?
Materials: newspaper * scissors * cardboard or Styrofoam egg carton * 2 hardboiled eggs per student * tape * ruler * paper and pencil * construction materials such as cotton balls, pipe cleaners, rubber bands, and cardboard scraps
Design a Solution:
1. Examine your eggs and helmet materials. Think about which materials would keep the eggshells from cracking during a collision.
2. Draw a plan for your helmet in the space below. Label the materials you plan to use.
3. Build your helmet around the egg.
4. What could you use to simulate a collision with your egg? Design a test for your helmet. Have your teacher approve your plan. Then test it.
5. Carefully remove the helmet and inspect your egg. Did it crack? If so, where? Record your observations.
6. Think about how you might change your prototype to better protect your egg. Repeat steps 2-5.
1. How did you test your helmet? Why did you decide to test it that way?
2. How well did your prototype helmet protect your egg?
3. What changes did you make to your prototype helmet to improve its design? Did your new design better protect your egg? Explain why or why not.
1. Answers will vary, but one way is to drop designs from the same height during each test. 2. Answers will vary. 3. Answers will vary, but students could add different materials to the inside of their helmets to cushion the fall. They could also add material to the outside of the helmet to spread the force of the impact over a larger area.
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|Title Annotation:||physical science|
|Date:||May 1, 2018|
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