As medianas de um triângulo
Lugares geométricos: Matematicamente Falando 9 - Parte 1 Pág. 97 Tarefa 10
- Desenha, em cartolina, três triângulos: um equilátero, um isósceles e um escaleno. Recorta-os.
- Em cada um deles, une cada vértice ao ponto médio do lado oposto.
Quantos segmentos de reta traçaste em cada triângulo? - Os segmentos de reta traçados em cada um dos triângulos têm algum ponto comum?
- Faz um pequeno orifício no ponto referido em 3. em cada um dos triângulos e, através dele, suspende o triângulo por um fio. O triângulo fica em equilíbrio numa posição horizontal?
- Explora a animação de geometria dinâmica.
Balancing a triangle on my pencil for extra credit…
This was a class project to learn how to use video in the classroom.
This is a quick explanation for finding the center of an object’s mass when the object has a consistent thickness throughout one dimension. The push-stick can be thought of as two-dimensional in a sense, because the plywood is 3/8″ no matter where we measure it. Because of this uniformity, z values will always be the same; thus, the center of mass is the average of all x and y values that the object occupies. The mass isn’t really “evenly spread all around the point,” so much as the point is the average location of the mass. Technically, the point is really inside of the wood, half-way through its thickness, but let’s try not to get too lost in the details ;)…
Demonstrations in Physics was an educational science series produced in Australia by ABC Television in 1969. The series was hosted by American scientist Julius Sumner Miller, who demonstrated experiments involving various disciplines in the world of physics. The series was also released in the United States under the title Science Demonstrations. This program was a series of 45 15 (or so) minute shows on various topics in physics, organized into 3 units: Mechanics, Heat and Temperature/Toys, and Waves and Sound/Electricity and Magnetism.
