What bodies have both potential and kinetic energy? a) Water in a mountain river

What bodies have both potential and kinetic energy? a) Water in a mountain river b) A motor ship adhered to the pier c) an airplane making a regular flight d) a rocket at the start

To answer this question, we present the general formulas of kinetic Ek and potential En energies:

Ek = m * v ^ 2/2, where m is body weight; v is the speed possessed by the body.

En = m * g * h, m – mass; g = 9.8m / s ^ 2, h is the body height above the Earth’s level, and consider each case:

a) the water in the river is at an altitude of h, and has potential energy, but also has a speed, which means that it can have En and Ek.

b) the ship at the pier does not yet have any energy;

c) the plane has speed, is at an altitude, has Ek and En.

d) the rocket at the start has Ek.

Answer: c) and a).