Concepts Of Physics MCQ Edition [Volume 1]
- Exam
- Concepts Of Physics MCQ Edition [Volume 1]
- Subject
- Physics
- Chapter
- Work and Energy
Concepts Of Physics MCQ Edition [Volume 1] · Physics · Work and Energy
A slide in a park possesses a total length of 10 ext m and a height...
A slide in a park possesses a total length of and a height of , as shown in the figure. A vertical ladder is provided to reach the top. A boy weighing ascends the ladder to the upper end of the slide, then slides down to the ground. The slide offers an average friction equal to three tenths of his weight. Determine the work done by the boy on the ladder as he goes up. Neglect any work done by forces inside the body of the boy.
Options
- A
- B
- C
- D
Correct answer
D.
Step-by-step solution
The work done by a force is defined as the dot product of the force and the displacement of its point of application, .
As the boy ascends, he applies a downward force on the steps of the ladder. However, the ladder is rigidly fixed to the ground and does not undergo any displacement.
Since the displacement of the point of application of the force is zero (), the work done by the boy on the ladder is zero.
As the boy ascends, he applies a downward force on the steps of the ladder. However, the ladder is rigidly fixed to the ground and does not undergo any displacement.
Since the displacement of the point of application of the force is zero (), the work done by the boy on the ladder is zero.