Mechanical Energy Flashcards
____ is said to be done whenever a force moves its point of application a distance in the direction of the force
Work
work is a ___ quantity
Scalar
If the force is at right angle to the displacement the force is said to be
Zero
An object held in the air is said to do no work if
It wasn moved through a distance d
A force is said to be conservative if
The force depends only on position and the workdone by the force on a particle moving btwn 2 positions depends on the initial and final positions
Example of conservative force is
Elastic and gravitational
An important feature of a conservative force is its
Recoverability
An example of a non conservative force is
Friction
_____ is device used for overcoming ___ at one end by application of effort on another end
Machine, load or resistance
The ability of machine to overcome heavy load through small load iscalled
Mechanical advantage
The MA is influenced byy
Friction in the parts
A machine that has no friction is called an
Ideal machine
Velocity ratio iss the ratio between the
Distance moved by the effort to the D moved by the load
Velocity ratio is dependent on the ___ of the machine and independent of the ____
Geometry and friction
The simplest machine is the___ based on the principle of ______
Lever, moments
In the first order lever the fulcrum can be found
In between the load and effort(scissors,crownbar,plier)
In second order lever the load is
In between fulcrum and effort (wheel barrow,,nutcracker)
In the third order lever the effort is
In between the fulcrum and the load(arm or biseps and tongs)
In a lever a special fact is that the
M.A=V.R
The most used machine is the
Pulley
In the first order lever velocity ratios
Are always greater than 1 but could be less thb or equal too
In Second order lever M.A and Vr are always
Greater than 1
In the third order V.R are always
Less than 1
In a pulley system the V.R is always equal to the
Number of pulleys
