Three metal balls of the same size, lead, steel and aluminum, are raised to the same height

Three metal balls of the same size, lead, steel and aluminum, are raised to the same height above the table. Which ball has the highest potential energy?

Given:

h1 = h2 = h3 = h – the height to which the balls were raised is the same;

V1 = V2 = V3 = V – the volume of the balls is the same;

ro1 = 11300 kg / m3 is the density of lead;

ro2 = 7800 kg / m3 – steel density;

ro2 = 2700 kg / m3 is the density of aluminum;

g = 10 m / s2 – acceleration of gravity.

It is required to determine which ball has the highest potential energy.

The potential energy of a lead ball will be:

W1 = m1 * g * h1 = ro1 * V * g * h = 11300 * 10 * V * h = 113000 * V * h.

The potential energy of a steel ball will be equal to:

W2 = m2 * g * h2 = ro2 * V * g * h = 7800 * 10 * V * h = 78000 * V * h.

The potential energy of an aluminum ball will be equal to:

W3 = m3 * g * h3 = ro3 * V * g * h = 2700 * 10 * V * h = 27000 * V * h.

Since W1> W2> W3 (113000 * V * h> 78000 * V * h> 27000 * V * h), the lead ball will have the maximum potential energy.

Answer: the ball of lead will have the maximum potential energy.