Chapter 10.1, Problem 20SSC

To determine

To Explain:Whether required work and power to lift a book depends on how fast it can be raised.

Explanation of Solution

Introduction:

Work done: $W=F\cdot s$

Here, F is the applied force and s is the displacement.

Power:

  $\begin{array}{c}P=\frac{W}{t}\\ =\frac{F\cdot s}{t}\\ =F\cdot v\end{array}$

Here, F is the applied force and v is the velocity.

In order to lift a book, the work requireddepends on the weight and the height of the shelf. It does not depend on how fast it is lifted. Since power depends on velocity, thus the power required to lift the book will depends on how fast it is lifted.

Conclusion:

Power required to lift the book depends on how fast it is lifted.