9781422274781

KEY ICONS TO LOOK FOR: in the air. There is also rotational energy created by the ball spinning around its center axis. The ball is also interacting with the Earth’s gravity, o the gravitational ne gy also is a f ctor. When a ball is spiraled, the linear kinetic energy is converted to rotational energy, meaning less energy to go higher. Sports Careers in STEM A hundred years ago, the first football helmets weren’t really helmets at all. Instea , they were le ther caps, offering li tle to no protection. STEM plays a big part in the design of today’s modern football helmets. A lot of engineering goes into creating the helmets to reduce the possibility of a player suffering a concussion. The National Football League (NFL) is very concerned about repeated concussions that lead to a serious brain disease called chronic tr umatic enceph lo athy (CTE). A Journ l of the American Medical Association study researched two hundred former football players and found that brain scans showed evidence of CTE in nearly all players. CTE is the reason why improved helmet design is needed. For example, today’s helmets have built-in accelerometers, a component that measures motion and velocity. All smart phones have accelerometers, and so do helmets, thanks to STEM. The accelerometers are built into the chin strap of the helmet to measure the force of the impact, as well as direction, to better help team doctors identify head injuries that might occur during the game. A great demonstration of this energy transfer is to watch a football bouncing down the field. If it is bouncing end over end, watch all the bounces. Are the later bounces higher than the first bounces? They probably are—as the ball is losing

Words To Understand: These words with their easy-to-understand definitio the reader’s understanding of the text while building vocabulary skills.

Sidebars: This boxed material within the main text allows readers to build k gain insights, explore possibilities, and broaden their perspectives by weavi additional information to provide realistic and holistic perspectives. Educational Videos: Readers can view videos by scanning our QR codes, pr with additional educational content to supplement the text. Examples inclu coverage, moments in history, speeches, iconic sports moments, and much

Text-Dependent Questions: These questions send the reader back to the t careful attention to the evidence presented there.

Research Projects: Readers are pointed toward areas of further inquiry con chapter. Suggestions are provided for projects that encourage deeper resea

Series Glossary Of Key Terms: This back-of-the-book glossary contains ter used throughout this series. Words found here increase the reader’s ability t comprehend higher-level books and articles in this field.

CHAPTER 1 : THROWING

15