Page 171 - WCS - Electrical

WORKSHOP CALCULATION & SCIENCE - CITS

Co-efficient of friction =tan (angle of friction)
Inclined plane
According to the figure, given below plane AB is inclined 0 to the horizontal. On this, the vertical line working at
Wkg weight will make an angle with normal line of the inclined plane equal to the degree of inclination of AB at
the horizontal.
The first component of weight W of the object acts on the normal line and is equal to w cos Ø. The second
component acts is equal to W sin Ø as shown in the figure.
Normal Reaction R=W cos Ø And
Limiting Friction Force F=W sin Ø
Co-efficient of friction µ = F/R
= W sin Ø /W cos Ø
=tan Ø
∑ Fx = 0

p = f + w ̅sin Ø
∑ fy = 0
R = w cos Ø
P = µ R + w sinØ ,
∴ F = µ R
P= µ (w cosØ )+w sin Ø ,
∴ Ø = µ
P= w tan Ø , cos Ø + w sin Ø P=w[sin Ø cos Ø + cos Ø sin Ø / cos Ø]\ P= w[ sin (Ø + Ø) / cos Ø]
P= w[ sin (Ø + Ø) / cos Ø]
Applications of Friction
1 Braking Systems: Friction is utilized in brakes to slow down or stop the motion of vehicles.
2 Traction: Friction provides grip between tires and road surfaces, ensuring vehicle stability and control.
3 Clutches: Friction clutches transmit power between rotating shafts by engaging and disengaging friction
surfaces.
4 Fasteners: Friction is utilized in screws, bolts, and nuts to hold components together securely.
Reducing Friction
- Lubricants, such as oils and greases, are used to reduce friction between moving surfaces by forming a thin
film that separates them.
- Surface treatments, such as polishing and coating, can reduce surface roughness and adhesion, thereby
minimizing friction.
Conclusion
- Friction is a fundamental force that affects various aspects of our lives, from everyday activities to industrial
processes.
- Understanding the causes, effects, and applications of friction allows us to optimize designs, improve efficiency,
and mitigate wear and tear in mechanical systems.

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CITS : WCS - Electrical - Exercise 15