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प्रश्न
A body, when acted upon by a force of 20 kgf, gets displaced by 1 m. Calculate the work done by the force, when the displacement is
- in the direction of force,
- at an angle of 60° with the force, and
- normal to the force. (g = 10 N kg-1)
उत्तर
F = 20 kgf = 20 × 10 N = 200 N
Displacement S = 1 m
Work done
- When displacement is in the direction of force
W = F × S
W = 200 × 1 = 200 J - When displacement is at an angle of 60°
W = F.S cos 60°
= 200 × 1 × `1/2`
= 100 J - When displacement is normal to the direction of force
W = F.S cos 90°
= 200 × 1 × 0
= 0 (Zero)
संबंधित प्रश्न
How is work done by a force measured when the force is in an angle to the direction of displacement?
How is the work done by a force measured when the force is in the direction of displacement?
A body is acted upon by a force. State two conditions when the work done is zero.
Choose one or more correct alternatives.
While dragging or lifting an object, negative work is done by ______.
- the applied force
- gravitational force
- frictional force
- reaction force
A force F acts on a body and displaces it by a distance S in a direction at an angle θ with the direction of force.
What should be the angle between force and displacement so that the work done is
- Zero
- Maximum
From the groups B and C, choose the proper words, for each of the words in group A.
| A | B | C |
| Work | Newton | erg |
| Force | Metre | cm |
| Displacement | Joule | dyne |
Explain the following concept in your own words with everyday examples:
Work
Explain the following concept in your own words with everyday examples:
Displacement
A cart with mass 20 kg went 50 m in a straight line on a plain and smooth road when a force of 2 N was applied to it. How much work was done by the force?
A force 'F' moves a load from A to C as shown in the figure below. For the calculation of the work done, which of these lengths would you use as the displacement?
