How Do Things Fall?
The collapse of certain very large stars creates a black hole, shown in this artist's conception. The gravitational force caused by a black hole is so great that even light cannot escape. Anything that enters a black hole disappears from the observable universe. A black hole has an infinite density and collapses space around it.Copyright NASA http://imagine.gsfc.nasa.gov/Images/news/BH_med.jpg
Students learn more about forces by examining the force of gravitational attraction. They observe how objects fall and measure the force of gravitational attraction upon objects.
We experience gravity so pervasively in our day-to-day lives that we may take it for granted. But, engineers must understand gravitational attraction when they design scales, elevators, airplanes, bridges and dams. And, since gravitational constants are different for places other than Earth, engineers must especially take gravity and weight into consideration when they design spacecraft, and moon or planetary vehicles.
After this lesson, students should be able to:
- Explain how gravity is a force that changes in space.
- Use measurements of the force of gravity acting upon a body to predict the force of gravity on other objects.
- Describe how engineers use their knowledge of gravity to design things like scales, elevators, airplanes, bridges and dams