View Factor Orientation (or View factor or shape factor) plays an important role in radiation heat transfer. View factor is defined as, "fraction of radiation leaving surface 'i' and strike 'j' ". Summation Rule (View Factor) If there is are similar surfaces 'i' and 'j' , then: Blackbody Radiation Exchange Radiation Exchange between Opaque, Diffuse, Gray surfaces in an Enclosure 1. Opaque 2. Surfaces 3. Two surface enclosure Radiation Shield It is used to protect surfaces from radiation act like a reflective surface. References: Material from Class Lectures + Book named Fundamentals of Heat and Mass Transfer by Theodore L. Bergman + My knowledge. Photoshoped pics are developed. Some pics and GIF from Google. Videos from YouTube ( Engineering Sights ).
If force acting on the body result in some traveled distance, then it is called work.
So, the formula for work done is given by:
The above formula can be written as:
There are three types of work which are described below:
Positive Work → If the angle between force and displacement is acute (0 < θ < 90).
Negative Work → If the angle between force and displacement is obtuse (90 < θ < 180).
Zero Work → If the angle between force and displacement is right (θ = 90).
Work Done By Variable Force:
If there is no constant force applied on an object for work done. The formula for work done by variable force is given by:
Work Done By Constant Force:
If constant force is applied on an object to displace from one point to other point but keep in mind it should be in a straight line. The formula for work done by constant force is given by:
Work Done By Weight:
The work done by an object having weight 'W' moving from 's1' to 's2' under the action of gravity is given by:
Work Done By Spring Force:
If we apply force on spring then it is elongated or compressed by a small distance 'ds'. The work done by the force on the spring in moving it from unstretched position to new final position is given by:
Applying 2nd equation of motion Ft = mat with at = v dv/ds, we get:
Since we know T = 0.5 x mass x square of velocity, so
Principle Of Work & Energy For System of Particles:
Principe of work and energy is applied on:
Enclosed region of space.
Work for which internal forces is zero.
For the system of particles, the principle of work and energy is given by:
There should be no energy loss due to particle interaction.
If there is energy loss → this equation cannot be used.
Types of Forces:
There are two types of forces which are described ahead:
Conservative Forces → If the work done by a force is independent of path followed, then it is called Conservative Forces. For e.g: weight, spring force, etc.
Non-Conservative Forces → Forces for which work done around a path is not zero and is dependent of path followed. For e.g: frictional force, etc.
Gravitational Potential Energy:
Energy due to height is called gravitational potential energy. This energy is given by:
Elastic Potential Energy:
The elastic potential energy (due to compression or elongation of spring) is given by:
Potential Function:
Potential function is the sum of gravitational and elastic potential energy. Its formula is given by:
Conservation of energy means: "Total energy of the system of particles remains constant if only the conservative forces doing work to the system".
Since, considering the work done by non-conservative energy is zero. So:
For the system of particles:
First we will learn statics and dynamics and then we will talk about why we need to learn these?
References:
Material from Class Lectures + Book named Engineering Mechanics Statics & Dynamics by R.C. Hibbeler (12th Edition) + from YouTube channel named Yiheng Wang for Engineering Dynamics Mechanics + my knowledge.
It depends on the scenario when and what equation to use. If there is a force acting on a body and displacement is shown then energy and work principle should be used. If there is a vertical displacement or no contact with horizontal during motion then use energy conservation. ******************************* For momentum and impulse equation: If there are non-conservative and conservative forces bith are present between bodies then use Impulse (Linear or Angular) and momentum principle. If there is only conservative forces present then use momentum conservation. Hope you will find your question's answer.
TAPING CORRECTIONS There are two types of corrections depending upon the type of errors in tape due to the different conditions. 1. Systematic Errors : Slope Erroneous tape length Temperature Tension Sag 2. Random Errors : Slope Alignment Marking & Plumbing Temperature Tension & Sag 1. Temperature Correction It is necessary to apply this correction, since the length of a tape is increased as its temperature is raised, and consequently, the measured distance is too small. It is given by the formula, C t = 𝛼 (T m – T o )L Where, C t = the correction for temperature, in m. 𝛼 = the coefficient of thermal expansion. T m = the mean temperature during measurement. T o = the tempe...
Projection: The term Projection is defined as: Presentation of an image or an object on a surface. The principles used to graphically represent 3-D objects and structures on 2-D media and it based on two variables: Line of Sight. Plane of Projection. Line of Sight & Plane of Projection: Line of sight is divided into 2 types: Parallel Projection Converging Projection & A plane of projection is an imaginary flat plane upon which the image created by the lines of sight is projected. Orthographic Projection: When the projectors are parallel to each other and perpendicular to the plane of projection. The lines pf sight of the observer create a view on the screen. The screen is referred to as the Plane of Projection (POP). The lines of sight are called Projection lines or projectors. Rules of Orthographic Projection: Edges that are parallel to a plane of projection appear as lines. Edges that are incl...
Types Of Lines And Its Uses: There are three types of types on the basis of thickness and they are: Visible Lines ↝ It represents features that can be seen in the current view. Hidden Lines ↝ It represents features that cannot be seen in the current view. Center Line ↝ It represents symmetry, path of motion, centers of circles,, axis of asymmetrical parts. Dimension and Extension Lines ↝ It indicates the sizes and location of features on a drawing. Placement Of Dimension Lines: Dimension should be outside the view. Dimension should be applied to one view. Dimension should be placed in a view that shows the distance in its true length. Dimension lines should be placed, in general 10 mm (1/2 in) away from the outlines from the view. Parallel lines should be placed uniformly. Values should be midway (auto centered) between the arrow heads, except when a center-line interferes. Dime...
When did i use conservation of energy and when i use principle of work and energy? I mean at what scenario?
ReplyDeleteIt depends on the scenario when and what equation to use.
ReplyDeleteIf there is a force acting on a body and displacement is shown then energy and work principle should be used.
If there is a vertical displacement or no contact with horizontal during motion then use energy conservation.
*******************************
For momentum and impulse equation:
If there are non-conservative and conservative forces bith are present between bodies then use Impulse (Linear or Angular) and momentum principle.
If there is only conservative forces present then use momentum conservation.
Hope you will find your question's answer.