Take control of a virtual car and learn how vectors are used to represent velocity and acceleration in this interactive activity developed for Teachers' Domain.
Students study the physical properties of different fluids and investigate the relationship between the viscosities of liquid and how fast they flow through a confined area. Student groups conduct a brief experiment in which they quantify the flow rate to understand how it relates to a fluid's viscosity and ultimately chemical composition. They explore these properties in milk and cream, which are common fluids whose properties (and even taste!) differ based on fat content. They examine control samples and unknown samples, which they must identify based on how fast they flow. To identify the unknowns requires an understanding of the concept of viscosity. For example, heavy cream flows at a slower rate than skim milk. Ultimately, students gain an understanding of the concept of viscosity and its effect on flow rate.
Join these kids as they investigate ramps by making a homemade hill to see what slides or rolls down it. [1:27]
Join Valerie and Margie as they devise ways to measure how fast and how "wild" two water slides are in this video from DragonflyTV. [3:12]
Students are introduced to an important engineering element the gear. Different types of gears are used in many engineering devices, including wind-up toys, bicycles, cars and non-digital clocks. Students learn about various types of gears and how they work in machines. They handle and combine LEGO spur gears as an exercise in gear ratios. They see how gears and different gear train arrangements are used to change the speed, torque and direction of a power source. This prepares them to apply this knowledge in four associated activities in order to create successful solutions to design challenges that use LEGO MINDSTORMS(TM) NXT robots. A PowerPoint® presentation, pre/post quizzes and a worksheet are provided.
Students are introduced to the concepts of force, inertia and Newton's first law of motion: objects at rest stay at rest and objects in motion stay in motion unless acted upon by an unbalanced force. Examples of contact and non-contact types of forces are provided, specifically applied, spring, drag, frictional forces, and magnetic, electric, gravitational forces. Students learn the difference between speed, velocity and acceleration, and come to see that the change in motion (or acceleration) of an object is caused by unbalanced forces. They also learn that engineers consider and take advantage of these forces and laws of motion in their designs. Through a PowerPoint® presentation and some simple teacher demonstrations these fundamental science concepts are explained and illustrated. This lesson is the first in a series of three lessons that are intended to be taught as a unit.
Students learn about friction and drag two different forces that convert energy of motion to heat. Both forces can act on a moving object and decrease its velocity. Students learn examples of friction and drag, and suggest ways to reduce the impact of these forces. The equation that governs common frictional forces is introduced, and during a hands-on activity, students experimentally measure a coefficient of friction.
Expanding on the topic of objects in motion covering Newton's laws of motion, acceleration and velocity, which are taught starting in third grade, students are introduced to new concepts of speed, density, level of service (LOS) (quality of roadways), delay and congestion. Every day we are affected by congestion even if we do not step out of our homes. For example, the price we pay for goods increases due to increases in shipping costs caused by congestion delays. A congestion metric would help us to compare roadways and assess improvement methods. A common metric used to measure congestion is called level of service (LOS).
In this open-ended design activity, students use everyday materials milk cartons, water bottles, pencils, straws, candy to build small-scale transportation devices. They incorporate the use two simple machines a wheel and axle, and a lever into their designs. Student pairs choose their materials and engineer solutions suitable to convey pyramid-building materials (small blocks of clay). They race their carts/trucks, measuring distance, time and weight; and then calculate speed.
In an interactive and game-like manner, students learn about the mechanical advantage that is offered by gears. By virtue of the activity's mechatronics presentation, students learn to study a mechanical system as a dynamic system under their control as opposed to a static image. The system presented is of two motorized racing cars built using the LEGO® MINDSTORMS® robotics platform. The altered variable between the two systems is the gear train; one is geared up for speed and the other is geared down for torque. Students collect and analyze data to reinforce particular aspects and effects of mechanical advantage.