Chapter_2 - Basic_Quantities

Chapter_2 - Basic_Quantities - Chapter 2 Basic Quantities...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 2 – Basic Quantities The basic quantities we use in our discussion of propulsion are called units. We have talked about force, mass, and acceleration. There are three basic units from which all other units are derived, mass distance, and time. We can define them both in the English system and the metric system. Metric units are much easier, but in the United States, the metric system has not been adopted in the field of aerospace except at NASA. We shall use both. The three basic units are: English Metric mass slug kilogram distance foot meter time second second Other common units are: speed change in distance time ft/sec (fps) m s area (L x W for rectangle) square feet (ft 2 ) m 2 acceleration change in vel time ft/s s (fts -2 ) m/s 2 Derived units are: force (from Newton's law F = ma) 2 slug ft lbf 5 Newton (N) 2 kg m 5 pressure force area 2 2 lbf lbf or (psi) ft in 2 N Pa = m A force can be thought of as a push or pull on an object. It can be balanced or unbalanced. For example, the book lying motionless on the table experiences a force downward called the gravitational force. It has magnitude, weight, and it has direction, downwards. The fundamental theory we will use in our study of the propulsion are Newtons (three) Laws of Motion. Newtons First Law – A body at rest will remain at rest and a body in motion will remain in
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/12/2011 for the course ASC 1640 taught by Professor Abbitt during the Spring '08 term at Santa Fe College.

Page1 / 3

Chapter_2 - Basic_Quantities - Chapter 2 Basic Quantities...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online