What is the meaning of 'Force Acting Obliquely'?
Sometimes, movement of body is not in direction of force applied
F force is applied in different direction but body moves in a different direction
This is called force acting obliquely or force acting indirectly
In this case, there is an angle between direction of force applied and direction of movement of object.
Example
When a child pulls a toy car with a string
force applied is in different direction but car moves forward in different direction (making an angle)
How to calculate work done in case of Force Acting Obliquely
In this case, we cannot use the formula
Work = Force × Distance
In this case, we cannot use Force because force is not in direction of movement of object
In this case, we cannot use the formula
So our formula becomes
Work = Force × Distance × cos θ
where θ is the angle between distance and force
Common Values of Cos θ
Some common values of cos θ for angles 0, 30, 45, 60, 90 are
DEGREE | COS THETA VALUE |
30 Degree | √3/2 |
60 Degree | 1/2 |
90 Degree | 0 |
180 Degree | -1 |
45 Degree | 1/√2 |
0 Degree | 1 |
Questions
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