MCQ
Q.
A boy raises a box with a weight of 120 N from a height of 2 m. The work done by him is ________.
Correct Answer: C
The correct answer is 240 J.
Key Points
- When a force is applied to an object which causes displacement along the direction of force then the work is said to be done by that force.
- The work done by a force is defined as "the product of the component of the applied force on the block in the direction of the displacement and the magnitude of this displacement" is called work done.
Additional Information
- i.e., \(W = \vec F.d\vec x = Fdx\cos \theta \)
or in terms of magnitude, it can be given as
\(W\; = \;F \times s\)
- Here both force and displacement will be along the same direction since force is causing this displacement thus Work done is a scalar quantity.
- Here,
- Force applied on object = F
- Displacement of object = dx
- Distance traveled by an object = s
- The angle between Force and displacement = θ
- Calculation:
- Given that,
- Person raised the box of weight 120 N through the height of 2 m
- i.e., F = 120 N
- x = 2 m
- Thus from the above explanation, we can see that
- Work = Force × Distance moved in the direction of the force
- Force of 120 N is acting downwards, Therefore
- Work Done = 120 × 2 = 240 J
