CH 10 - Projectile and Satellite Motion Flashcards
Projectile Motion
the only force acting is gravity and once projected continues in motion by its own inertia and is influenced only by the downward force of gravity.
Examples of projectile motion
an object dropped from rest is a projectile, an object which is thrown vertically upwards is also a projectile and an object is which thrown upwards at an angle is also a projectile
Projectiles Launched Horizontally
The trajectory of a projectile that accelerates only in the vertical direction while moving at a constant velocity is a parabola.
Projectiles Launched at an Angle
The projectile moves in a vertical plane.
The launching angle determines the shape of parabola.
The y-axis changes as the projectile moves.
The x-axis stayes the same as the projectile moves.
Satellites
A projectile falls 5 m in a second. The Earth’s curvature drops 5 m on 8000 m distance.
What should be the speed for a projectile to be in a state of continuous fall around Earth?
8,000 m/s
An orbit is the sequence of positions in space of a star or artificial satellite in motion around
Another more massive star.
An orbit’s trajectory is not random, but dictated by the
laws of universal gravitation.
Elliptical Orbits
When velocity is above 8 km/h the orbit becomes elliptical.
The Earth does not spin in a perfect rotation
Oval
It’s off by 8 degrees
Energy Conservation & Satellite Motion
two components of the attraction force, one that changes the speed and one that changes the direction.
The changes in speed are consistent with the work-energy relationship
With an elliptical orbit Kinetic + potetial energy are
Equal to their opposite ends
With a perfect orbit Kinetic + Potetial energy are
Circle
Equal
Escape speed
The minimum speed required for an object to escape a planet’s gravitational attraction.
