A 1.6 kg rock initially at rest loses 404 J of potential energy while falling to the ground. Assume that air resistance is negligible.
Calculate the kinetic energy that the rock gains while falling.
What is the rock's speed just before it strikes the ground?
m/s

Explanation:

The point about the question is that if PE is lost, then KE must be gained.

So the answer to the first part is 404 Joules.

Unless the total kinetic energy gained is 404 joules, the problem is impossible to calculate the second part. We'll assume that the 404 is the total amount of energy gained by the object.

KE = 404

PE = 0

KE = 1/2 m v^2

KE = 404

m = 1.6

404 = 1/2 1.6 kg * v^2       Multiply 1.6 and 1/2 which is 0.8

404 = 0.8 kg * v^2            Divide both sides by 0.8

404/0.8 = v^2

505 = v^2                          Take the square root of both sides.

v = 22.47 m/s

Just before hiting the ground the speed is 22.47 m/s

the largest known star in the universe is uy scuti, a hypergiant with a radius around 1,700 times larger than the sun.jul 26, 2018

explanation:

an ion is a charged atom or molecule. it is charged because the number of electrons do not equal the number of protons in the atom or molecule. an atom can acquire a positive charge or a negative charge depending on whether the number of electrons in an atom is greater or less then the number of protons in the atom.