A student librarian picks up a 2.2 kg book from the floor to a height of 1.10 m. He carries the book 7.9 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=force(netdisplacement)=mg*(.35)

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To find the amount of work the student librarian does on the book, we need to calculate the work done in three stages: lifting the book, carrying it horizontally, and placing it on the shelf.

1. Lifting the book:
The work done in lifting the book is given by the formula: work = force x distance x cos(theta), where force is the weight of the book, distance is the vertical distance moved, and theta is the angle between the force and the direction of movement.

The weight of the book can be calculated using the formula: weight = mass x gravitational acceleration.
Here, the mass of the book is 2.2 kg and gravitational acceleration is approximately 9.8 m/s^2.

So, weight = 2.2 kg x 9.8 m/s^2 = 21.56 N.

The vertical distance moved is 1.10 m.

Since the lifting force is acting upward and the displacement is also upward, theta = 0 degrees. The cos(0) = 1.

Therefore, work done in lifting the book = weight x distance x cos(theta) = 21.56 N x 1.10 m x 1 = 23.71 Joules.

2. Carrying the book horizontally:
No vertical displacement is involved in carrying the book horizontally. Therefore, no work is done in this stage.

3. Placing the book on the shelf:
The work done in placing the book on the shelf is again given by the formula: work = force x distance x cos(theta).

The weight of the book is the same as before, 21.56 N.

The vertical distance moved is 0.35 m.

Since the force is acting upward and the displacement is downward, theta = 180 degrees. The cos(180) = -1.

Therefore, work done in placing the book on the shelf = weight x distance x cos(theta) = 21.56 N x 0.35 m x -1 = -8.71 Joules.

Adding up the work done in each stage, the total work done by the student librarian on the book is:

23.71 Joules + 0 Joules + (-8.71 Joules) = 15 Joules.

Therefore, the student librarian does 15 Joules of work on the book.

To calculate the work done by the student librarian on the book, we need to use the formula:

Work = force × distance

In this case, the force applied by the student librarian is equal to the weight of the book, and the distance is the height the book is lifted plus the distance it is carried.

First, let's calculate the work done while lifting the book:

Force = Weight
Weight = mass × gravity

The mass of the book is given as 2.2 kg, and the acceleration due to gravity is approximately 9.8 m/s^2. Therefore, the weight of the book is:

Weight = 2.2 kg × 9.8 m/s^2

Next, we need to calculate the height the book is being lifted. This is given as 1.10 m.

So, the work done in lifting the book is:

Work_lift = Weight × height

Next, we need to calculate the work done while carrying the book:

Distance = 7.9 m

The weight of the book remains the same, so the work done in carrying the book is:

Work_carry = Weight × distance

Finally, we need to calculate the additional work done to place the book on the shelf. The height of the shelf is given as 0.35 m, and the weight of the book remains the same. Therefore, the work done to place the book on the shelf is:

Work_place = Weight × height

To find the total work done, we add up all three components:

Total work = Work_lift + Work_carry + Work_place

Substituting the respective values, we can calculate the total work done by the student librarian on the book.