# Water Slides

#### Early Engineers

This week, Early Engineers learned about physics with these wacky water slides!

A water slide is similar to a roller coaster. Many of the same design elements apply: the shape and height of the slide determines how fast you will go. The purpose of the water in the water slide is to reduce friction, the force that resists motion when the surfaces of two objects are in contact. Friction will slow you down. Since the water reduces friction between the person and the slide, the person will move pretty fast down the slide.

An object that is moving, like a person sliding down a slide, has momentum. Momentum is a measurement of mass in motion: the amount of momentum an object has depends on how much mass is moving and how fast. Both the speed of the object and the mass have an equal impact on the amount of momentum. You have more momentum when you are running than when you are walking. This is because you are moving faster when you are running. If a car and a bicycle are traveling down the street at the same speed, the car till have more momentum. This is because the car is much heavier than the bicycle.

We also learned about inertia. Inertia is “The First Law of Motion”. An object in motion will stay in motion unless acted on by an outside force. An object at rest will stay at rest unless acted on by an outside force. It means if something is moving, it will keep moving until something stops it. If something is not moving, it will stay there until something comes along to move it. If you put a book on a table... It would just sit there unless you moved it. You could pick it up... or push it... or lift one side of the table so it would slide off. That's inertia!

Instead of people and full sized water slides, our Early Engineers built their slides this week with ping pong balls, marbles, plastic cups, tape, and pipe insulation. we were able to see the laws of motion, inertia, and momentum in action as our crazy courses ran throughout the classroom from desks and up and all around chairs and other obstacles. Learning about physics has never been so much fun!

We hope you and your little builder enjoyed this week's water-less water slides. Join us again next week, where we'll make a piece of working construction equipment!