When something accelerates, it changes how fast it is going or the direction in which it is moving. It is said to be instantaneous because, in a circular motion, the direction is constantly changing, which is why there is an acceleration and a force.Īcceleration: How fast the velocity is changing. Tangential velocity: The instantaneous velocity in a straight line of an object moving in a circular motion. “The rollercoaster was moving at 65 mph when Billy got sick” is a measure of speed. “The car was going 65 mph south on I-95” is a measure of velocity. Not to be confused with speed, which is only how fast something is moving. Velocity: A measure of how fast something is going in some specific direction. For example, the air resistance that we saw when objects fell in activity one, or the resistance you feel while swimming in a pool when the water slows you down. For example, gravity is a force that represents the pull the Earth has on all the objects.Ĭentripetal force: The generic name of any force that pulls objects into a circular path.ĭrag force: A generic name for any force that resists the movement of the objects. It is formally defined as mass times acceleration. If the interaction stops, then there is no force. However, your mass will still be the same.įorce: The push or pull an object feels because of interactions with other objects. This means that your weight on the moon will be 1/6 of that on Earth (gravity on the moon is 0.166 times of that on Earth). Weight: Mass (amount of stuff) times how hard the planet is pulling on it (gravity). This is a measure of how much actual stuff there is, not how big it is or how hard something is pulling on it. Not to be confused with weight or volume. Mass: A measure of the amount of stuff (or matter) an object has. An object that moves in a circular motion will have the same average velocity and altitude of an object in an elliptical orbit.įor more information and ideas on how to implement the activity in your classroom check out the video. Though you may think that an ellipse is a different shape from a circle, circles are actually a special type of elliptical shape. r = p 1 + e c o s θ This complex equation is just the start in finding the distance of the satellite for Earth’s center. The equation that she used is one where a body (such as one like our satellite) acted upon by a radial force of attraction proportional to the inverse square of the distance are first reviewed. For this particular equation, Johnson worked with elementary celestial mechanics, a branch of astronomy that deals with objects in outer space. Satellites in space orbit the Earth, just like the Moon orbits around the Earth. In this paper Katherine Johnson was working on finding the right moment to turn off a satellite’s engine so that it would land on a specific position on Earth. Examples of circular motion are carousels or merry-go-rounds in parks, a car going around a roundabout, the moon orbiting around the Earth or the Earth revolving around the Sun. In this last activity, we are combining all that knowledge to see what happens when objects move in circular motion: there are constant changes in the horizontal and vertical direction at all times during the movement, making the object follow a circular path. We also looked at what happens when objects fall while also moving in the horizontal direction. We have already looked at motion of objects falling in one direction when you drop it, or in two directions as part of a pendulum.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |