14. a student lifts a 0.5 - kilogram book to a height of 0.4 meters from a lab table, and carries it across…

14. a student lifts a 0.5 - kilogram book to a height of 0.4 meters from a lab table, and carries it across the room at a distance of 3 meters. how much work does a student do when she lifts the book? 1.2 j 1.5 j 2.0 j 2.5 j clear all

14. a student lifts a 0.5 - kilogram book to a height of 0.4 meters from a lab table, and carries it across the room at a distance of 3 meters. how much work does a student do when she lifts the book? 1.2 j 1.5 j 2.0 j 2.5 j clear all

Answer

Explanation:

Step1: Calculate the force

The force (F) needed to lift the book is equal to its weight. Using the formula (F = mg), where (m = 0.5\space kg) and (g= 9.8\space m/s^{2}). So (F=0.5\times9.8 = 4.9\space N).

Step2: Calculate the work - done

The work - done (W) in lifting the book is given by the formula (W = Fd), where the distance (d) is the height (h = 0.4\space m) (the direction of the force and the displacement are in the same direction when lifting). So (W=4.9\times0.4=1.96\approx2.0\space J).

Answer:

2.0 J