What is the mass of an apple if it had a kinetic energy of about 10 J before hitting the ground?

Given:

E = 10 Joules – kinetic energy of the apple before hitting the ground;

g = 10 Newton / kilogram – acceleration of gravity.

It is required to determine m (kilogram) – the mass of the apple.

Since it is not specified in the problem statement, we assume that the apple fell without initial speed from a height equal to h = 4 meters (the approximate height of the tree). Then:

E = E potential = m * g * h, hence:

m = E / (g * h) = 10 / (10 * 3) = 1/4 = 0.25 kilograms (250 grams).

Answer: The mass of an apple is 0.25 kilograms (250 grams).