Page 180 - WCS - Electrical

WORKSHOP CALCULATION & SCIENCE - CITS

= Load x Distance moved by load

F1 .L = F2. h
F1 = F2 . h\L = F2 . sin α
Where h= opposite side
L= Length of inclination i.e., hypotenuse
F1= Effort i.e., Applied force

F2= Load
α = Angle of inclination of inclined plane
F1=F2 . sinα
This principle is used in moving or lifting heavy loads to certain height.

Applied Force Parallel to the Horizontal
Effort x Distance moved by effort
= Lcad x Distance moved by load
F .I= F2 . h
1
F1 = F2 . h\I =F2 . tan α
F1 = F2 . tan α

This principle is used in keys.
where: F1 = Effort i.e., Applied force
F = Load
2
h = opposite side

I = Adjacent side
α = Angle of inclination of inclined plane
Let d = diameter of screw and
h = pitch of screw
In such a case:

tan α = h\i = pitch of screw\Circumference of screw
Example
A mass of 300 kg is to be pulled up an inclined plane
having 30° of angle of inclination. Calculate the pulling force.
Solution: Pulling force= 300 kg x sin 30°

=300kg x 1\2
= 150 kg
=150 x 9.8 newtons
= 1470 newtons
2 Lever

- A lever consists of a rigid bar (lever arm) that pivots around a fixed point called the fulcrum.
- Levers can be categorized into three classes based on the relative positions of the fulcrum, effort, and load.
- They are used to amplify force (e.g., crowbar), change the direction of force (e.g., seesaw), or increase the
speed of movement (e.g., scissors).

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CITS : WCS - Electrical - Exercise 17