How much work is done by gravity when a pine cone (of mass 50g) falls from the top of a tree, 9 m high?

Answer: 4.41 joules

Explanation:

Given that:

work is done by gravity = ?

Mass of pine cone (m) = 50g

Convert mass in grams to kilograms

Since 1000g = 1kg

50g = (50/1000) = 0.05kg

Height of tree (h) = 9 m

Apply the formula for work,

Work = mass x acceleration due to gravity x height

Acceleration due to gravity has a value of 9.8m/s^2

Work = mgh

Work = 0.05kg x 9.8ms^2 x 9m

Work = 4.41J

Thus, 4.41 joules of work is done by gravity.