Isaac Newton y la gravedad Una fuerza invisible

Gravedad Cada objeto atrae a los demás con una fuerza invisible llamada fuerza de gravedad. Hay fuerza de gravedad entre tú y tu carrito de juguete, pero no la notas porque es muy débil. Every object pulls on every other object with an invisible force called gravity. There is gravity between you and your toy car, but you won’t notice it because it is so weak.

Gravedad Sin embargo, puedes sentir la atracción entre tú y la Tierra. Eso se debe a que la fuerza de gravedad depende de la masa del objeto y la Tierra tiene una masa muy grande. You can, however, feel the pull between you and the Earth. That’s because the force of gravity depends on an object’s mass, and the Earth has a lot of mass.

La fuerza de gravedad La Tierra tiene tanta masa que atrae todo hacia su centro incluyendo a los océanos y el aire. The earth has so much mass, that it pulls everything downward toward its center, including the oceans and air. Even the moon stays above the Earth because of gravity. Aún la Luna permanece sobre la Tierra debido a la fuerza de gravedad.

Isaac Newton Hace aproximadamente 300 años un científico llamado Isaac Newton explicó esta fuerza invisible, la fuerza de gravedad. Over 300 years ago, a scientist named Isaac Newton explained this invisible force of gravity.

El descubrimiento de Newton Newton estaba sentado en su jardín cuando vio que una manzana caía de un árbol. Concluyó que alguna fuerza debía estar atrayendo la manzana hacia el suelo. La llamó fuerza de gravedad. Newton was sitting in his garden when he saw an apple fall from a tree. He decided that some force must be pulling the apple to the ground. He called it gravity.

Pon a prueba tus conocimientos Ya sabes mucho acerca de la fuerza de gravedad. Eso se debe a que constantemente está actuando sobre ti. Pongamos a prueba tus conocimientos. You already know a lot about gravity. That’s because it’s at work all the time. Let’s test your knowledge.

¿Está actuando la fuerza de gravedad? sí o no Is gravity at work in this picture? Yes Describe how gravity is affecting the motion of the student on the slide. Gravity is pulling the student down the slide. How did the position of the student change? The student moved from the top of the slide to the bottom. Is it easier to come down the slide or climb up it? It is easier to slide down the slide because gravity must be overcome (with the force of your bones and muscles) to climb up the slide.

¿Está actuando la fuerza de gravedad? si o no Is gravity at work in this picture? Yes Describe how gravity is affecting the movement of the plant. Gravity causes the roots to grow down toward the center of the Earth. How is the plant overcoming gravity? The stems and leaves are growing up toward light.

¿Está actuando la fuerza de gravedad? sí o no Is gravity at work in this picture? Yes Describe how gravity is affecting the movement of the basketball. The basketball was thrown up, but gravity is pulling it down through the net (one hopes). Think about what a diagram of the movement of this basketball would look like. How might we sketch its starting point, its movement through the air to its ending position? Students could sketch a diagram on the board to show the basketball’s movement. It will not move in a straight line, but will arch in the shape of a parabola. What types of things do people who play sports wear which protects them from the effects of gravity (falls)? Answers may include helmets, knee pads, face masks, etc.

¿Está actuando la fuerza de gravedad? sí o no Is gravity at work in this picture? Yes Describe how gravity is affecting the movement of the rain. It is pulling the rain to the ground. Can you think of other ways that gravity affects the movement of water? Answers will vary, but may include the movement of water down a waterfall, down streams and rivers, from a pitcher to a cup, etc.

¿Está actuando la fuerza de gravedad? sí o no Is gravity at work in this picture? Yes How does gravity help the diver? It pulls the diver into the pool.

¿Está actuando la fuerza de gravedad? sí o no Is gravity at work in this picture? Yes Describe how gravity is affecting the movement of the water. It pulls the water downward from the faucet. Why might water towers be built far above the ground? There are several reasons, but gravity helps the water move from the higher location to the ground pipes which carry the water to our homes.

¿Está actuando la fuerza de gravedad? sí o no Is gravity at work in this picture? Yes Describe how gravity is affecting the movement of the rider and bicycle. Gravity is pulling the rider and bicycle down the sloping mountain. Would it be easier to ride down the path or ride up it? It is easier to ride down the slope. The rider is coasting and using the force of gravity to pull him down the slope.

¿Está actuando la fuerza de gravedad? sí o no Is gravity at work in this picture? Yes Describe how gravity is affecting the movement of the yo-yo. Gravity allows the yo-yo to drop down along the string. What keeps the yo-yo from falling to the ground? Your hand supplies a force (pull upward) which keeps the yo-yo from falling to the ground.

¿Está actuando la fuerza de gravedad? sí o no Is gravity at work in this picture? Yes How do you know it is working? If it were not working, the student would float into the air and not be able to sit down in the desk.

Venciendo la fuerza de gravedad Podemos vencer la fuerza de gravedad, pero tenemos que usar otra fuerza para hacerlo. We can overcome gravity, but we have to use force to do it. (Point out the force arrows in the pictures. Be sure students equate the down arrow with the force of gravity, and the upward arrow with the force used to overcome gravity.)

Más sobre la fuerza de gravedad ¡Espera! ¡Lo demás está por venir! Hang On! There’s More to Come!

Picture Credits Pictures are courtesy of Microsoft clip art.