Ninth Grade, Mechanical Engineering Science Experiments (Page 2)

Effect of Trebuchet Arm Length or Counterweight Mass on Projectile Distance

Science Fair Project Idea

Engineering Design Process

Before cannons widely replaced them, siege engines were often used by armies to throw large stones and other projectiles to break down castle walls. One of the most advanced siege engines used in the Middle Ages was the trebuchet, which used a large counterweight to store energy to launch a payload, or projectile. The horizontal distance the payload would travel is called the trebuchet's range. Figure 1, below, shows a modern reconstruction of a trebuchet. The range of a trebuchet has always… Read more

Find the Best Pinwheel Design

STEM Activity

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Wind energy is becoming more and more popular across the United States, maybe you have even seen a wind farm close to where you live! In 2015, approximately 7% of the electricity used in the U.S. was generated by wind, so who knows, when you switch on a light bulb in your house, that light might be coming from wind energy! Wind energy is generated by wind turbines. These machines can look like giant pinwheels, and their job is to turn energy from the wind into mechanical or electrical energy.… Read more

Make the Fastest Rubber Band Paddle Boat

Science Fair Project Idea

Engineering Design Process

Rubber band paddle boats are a fun bathtub or pool toy that you can build yourself. How do you make a boat that goes the fastest? Find out in this project as you build and test your own boat. 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

Build an 'Impossible' Wind-Powered Car

Science Fair Project Idea

Engineering Design Process

Is it possible for an entirely wind-powered vehicle to travel directly downwind faster than the wind? This might seem counterintuitive or like it would violate the law of conservation of energy. After all, any good scientist knows that perpetual motion machines are impossible. However, as demonstrated by YouTubers Rick Cavallaro, Derek Muller (Veritasium), and Xyla Foxlin, you can take advantage of some tricky physics to make this vehicle work. Can you build—or even improve—your own… Read more

Click a Button Without Your Hands: Design a Puff Switch

Science Fair Project Idea

Engineering Design Process

Have you ever wondered how you could push a button without using your hands? How would you type on a computer or play a video game? You could use a puff switch - an electronic switch activated by blowing into a straw. This type of assistive device can help users with limited mobility or physical disabilities do everything from using a computer to steering a wheelchair. In this project, you will design, build, and test a puff switch that is connected to a tiny programmable board that you can use… Read more

Protect Your 'Eggstronaut': Build an Egg-Drop Lander

STEM Activity

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The egg-drop project is a classic and time-honored tradition in many science classes. The goal is usually to build a device that can protect an egg when dropped from a high location. This activity puts a twist on the classic project, motivated by real-world advances in space exploration. Can you build a reusable egg-drop lander that can survive repeated falls from the same height? Try this activity and find out 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

Effect of Friction on Objects in Motion

Science Fair Project Idea

Scientific Method

The funny thing about friction is that you couldn't get anywhere without it, yet it still acts to slow you down as you're getting there. Here is an easy project to measure the effects of friction. Read more

Volleyball Machine Challenge

Science Fair Project Idea

Engineering Design Process

Can you build a volleyball machine? It will need one part to launch a ping pong ball over a net and another to return the ball. How many back-and-forth volleys can you get before the ball touches the ground? Looking for inspiration? You can see how other students have tackled this and other annual Science Buddies Engineering Challenges. Teachers, lesson plan versions of this challenge are available. Read more

Ninth Grade, Mechanical Engineering Science Experiments (77 results)

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