Find the potential energy of a 400-gram bar raised to a height of 120 cm from the earth’s surface.

m = 400 g = 0.4 kg.

g = 9.8 m / s2.

h = 120 cm = 1.2 m.

Ep -?

The potential energy of a bar En with mass m, raised to a height h above the earth’s surface, is a scalar physical quantity, the value of which is determined by the formula: En = m * g * h, where g is the acceleration of gravity.

The potential energy of the bar En shows what kind of mechanical work A it can perform.

Ep = 0.4 kg * 9.8 m / s2 * 1.2 m = 4.7 J.

Answer: the bar has a potential energy of En = 4.7 J.