1 / 26

# Chapter 5 Projectile Motion and Satellites - PowerPoint PPT Presentation

Chapter 5 Projectile Motion and Satellites. Projectile Motion. Describe the motion of an object in TWO dimensions Keep it simple by considering motion close to the surface of the earth for the time being Neglect air resistance to make it simpler. Projectile Motion.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about ' Chapter 5 Projectile Motion and Satellites' - dean-parker

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Chapter 5Projectile Motion and Satellites

Describe the motion of an object in TWO dimensions

Keep it simple by considering motion close to the surface of the earth for the time being

Neglect air resistance to make it simpler

The ball is in free fall vertically and moves at constant speed horizontally!!!

Adds a new force on the ball

The force is in the opposite direction to the ball’s velocity vector and is proportional to the velocity at relatively low speeds

Need calculus to sort out the resulting motion

Lowers the angle for maximum range

Projectile Motion

The trick to maximum range is just to keep the object off the ground for as long as possible.

This allows the horizontal motion to be a maximum since x = vxt

Make range longer by going higher for your starting point

Make range longer by having more velocity

Projectile Motion

Projectile Motion the ground for as long as possible.

Curvature of the earth enters into our calculations the ground for as long as possible.

Satellites

If I start 5 m above the surface, it will still be at 5 m after one second if it is moving 8000 m/sec

Satellites the ground for as long as possible.

Throw at 8000 m/sec

Earth circumference is 25,000 miles

Takes 25000/18000 = 1.4 hours = 84 minutes

Higher altitude longer

Satellites the ground for as long as possible.

Force of gravity on bowling ball is at 90o to velocity, so it doesn’t change the velocity!!!

If no air resistance, gravity doesn’t change speed of satellite, only direction!!!

It takes longer for the trip

Also, gravity weakens by inverse square law the farther out you go

Make the distance so that it takes 24 hours for the orbit

Satellite is stationary in the sky!!!

Communications Satellites

Takes 27.3 days to make an orbit

The Moon

Give the object a speed a bit greater than 8 km/sec and the orbit will be elliptical

Elliptical Orbits

Elliptical Orbits orbit will be elliptical

Elliptical Orbits orbit will be elliptical

Sum of distances from foci to point on the ellipse is a constant!!!

Each planet moves in an elliptical orbit with the sun at one focus of the ellipse.

The line from the sun to any planet sweeps out equal areas of space in equal time intervals

The squares of the periods of the planets are proportional to the cubes of their average distances from the sun

Kepler’s Laws

Kepler’s Laws focus of the ellipse.

Energy Conservation focus of the ellipse.

Energy Conservation focus of the ellipse.

Energy Conservation focus of the ellipse.

Escape Speed focus of the ellipse.

Throw at > 11.2 km/sec and ball escapes the pull of the earth!!!