You do 200 joules of work against gravity when lifting your backpack up a flight of stairs that is 4 meters tall. What is the weight of your backpack in newtons?

Correct answer: F = 50 N weight of backpack

Explanation:

Given:

W = 200 J work against gravity

h = 4 m

F = m g = ?

g = 10 m/s²

The work done is a measure of change in this case of potential energy

W = Δ Ep = m g h = F · h ⇒ F = W / h =

F = W / h = 200 / 4 = 50 N

F = 50 N

God is with you!