That's false. Think about a stone or a baseball, during the first
several seconds after you tossed it straight up, before it reaches
its maximum height and starts to come down again.
There's no upward force on it during that time.
Also, after a roller coaster reaches the top of the FIRST hill, there's
no upward force on it for the whole rest of the ride, even though it
coasts up many more hills.
Answer:
1800J
Explanation:
Given parameters:
Weight of the book = 20N
Total distance covered = 45m + 15m + 30m = 90m
Unknown:
Total work performed on the books = ?
Solution:
To solve this problem we must understand that work done is the force applied to move a body through a certain distance.
So;
Work done = Force x distance
Work done = 20 x 90 = 1800J
