A student librarian picks up a 2.2 kg book from the floor to a height of 1.15 m. He carries the book 8.4 m to the stacks and places the book on a shelf that is 0.35 m above the floor. How much work does he do on the book?
work= mgh h=(1.15+.35) walking horizontally, no work is done
To determine the amount of work the student librarian does on the book, we need to calculate the work done in both lifting the book and carrying it.
1. Work done in lifting the book:
The work done in lifting an object is given by the formula: W = m * g * h, where W is the work done, m is the mass of the object, g is the acceleration due to gravity (approximately 9.8 m/s^2), and h is the height.
Given:
- Mass of the book (m) = 2.2 kg
- Height lifted (h) = 1.15 m
Substituting the values into the formula, we have:
Work = 2.2 kg * 9.8 m/s^2 * 1.15 m
Work = 25.34 Joules
The work done in lifting the book is 25.34 Joules.
2. Work done in carrying the book:
The work done in carrying an object horizontally without vertical displacement is zero because the force is applied perpendicular to the displacement.
Therefore, the work done in carrying the book is zero.
Thus, the total work done by the student librarian on the book is 25.34 Joules.