Eighth Grade, Mechanical Engineering Science Projects (Page 2)

How Do Under-Inflated Tires Affect the Difficulty of Riding a Bike?

Science Fair Project Idea

Scientific Method

If you ride a bike, you probably know that you have to occasionally pump up the tires to keep them fully inflated. Over a long period of time, the tires slowly leak air, so their pressure will decrease. Have you ever noticed that it is actually harder to ride a bike when the tire pressure is too low? This is because the tires are a big factor in the rolling resistance of the bike. In this sports science project, you will measure how tire pressure affects the force required to move a bike. How… Read more

How Does Spark Plug Gap Affect Engine Performance?

Science Fair Project Idea

Scientific Method

Do you know what a spark plug is? Have you ever replaced an old, dirty, or worn out spark plug in an engine? These small parts are crucial to the operation of internal combustion engines. In this science project, you will find out how "gapping" a spark plug affects engine performance. Can you get more power or better fuel economy out of your engine by changing the spark plug gap? Try this project and find out! Read more

Lift a Load Using Hydraulics

Science Fair Project Idea

Scientific Method

Can you lift a car? No? You say you are not strong enough? True, our bodies are not built to lift heavy loads like cars. Fortunately, our brains are smart enough to harness the power of fluids, like water and oil, to create hydraulic lifts. By pushing a button on a hydraulic lift, a mechanic can easily raise a car with one finger. Lifts can also be used to raise lots of other heavy loads - even such massive things as steel girders to construct a skyscraper! In this mechanical engineering… Read more

Marble Machine

Science Fair Project Idea

Engineering Design Process

Put your engineering skills to the test to see if you can build a machine—powered by nothing but gravity—that will automatically sort out two different sizes of plastic spheres. That might seem like a strange task, but have you ever used a coin sorter to separate pennies, nickels, dimes, and quarters? How about using a sifter in the kitchen to separate fine grains of flour or sugar from bigger lumps? Machines that can automatically sort objects or particles of different sizes are… Read more

Measuring Vibrational Frequency with Light

Science Fair Project Idea

Scientific Method

Strike a key on the piano, and you hear the string vibrating. Just about any object vibrates when it's knocked, but how much and how fast? What properties of the material affect the way it vibrates? This project helps you find out. You'll build a simple light-sensing circuit for measuring the frequency of vibrating springs. Read more

Mix It Up: Transferring Heat by Convection in a Tank

Science Fair Project Idea

Scientific Method

Big, puffy, cotton-like clouds, and the bubbles in a pot of boiling water may not seem like they have much in common, but they do—both are formed by a heat-transfer process called convection. Warmed gases and liquids rise, while cooler ones fall, creating currents and mixing things up. Whether making processed foods in a factory or making plastic or metal parts, knowing how to mix up a big tank of hot and cold liquids or gases quickly is important. Engineers must rely on experimentation… Read more

Rubber Band Elasticity and Temperature

Science Fair Project Idea

Scientific Method

Many materials expand when heated and contract when cooled. What do you think will happen to the elasticity (stretchiness) of a rubber band when it is heated or cooled to various temperatures? Read more

Slippery Slopes and Sticking Surfaces: Explore the Forces of Friction

Science Fair Project Idea

Scientific Method

Whoopee! No matter what age, who doesn't like flying down the slides at parks and pools? In this experiment, you might be surprised what you can learn about the fascinating forces of friction while sliding down (or sticking to) those fun, slippery slopes. Caution: only speed demons need apply for this activity. Read more

The Chills and Thrills of Roller-Coaster Hills

Science Fair Project Idea

Scientific Method

Think it's a good idea to stream music, watch videos, or check social media while doing homework? Are you a thrill-seeker? Well, this is the science fair project for you! What makes a ride so thrilling that people want to ride it over and over again even though it scares them? Is it the speed, the twists and turns, the vertical drops? In this science fair project, you will build and use an accelerometer to figure out what makes a roller-coaster ride worth standing in line for. Oh, and if Mom… Read more

The Turn of the Screw

Science Fair Project Idea

Scientific Method

How much force is required to advance a lag bolt (large wood screw with a hex-shaped head) into a piece of wood? You can measure the force by using a spring scale attached to the handle of ratchet. Pull on the spring scale until the bolt starts to turn, and note the required force from the spring scale. There are many potential experiments you could try. Think about answering the following questions: How does the force change as the bolt advances deeper into the wood? Why? How does the… Read more

Eighth Grade, Mechanical Engineering Science Projects (21 results)

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