Question

Calculate the potential energy of an object of mass 50 kg raised to a height of 4 m above the ground. If the object falls down, what is the kinetic energy when it has fallen through 2 m? Take g= 9.8m/s².

Answer 1

Dear Student,

Potential energy can be calculated as: mgh = 50 $\times$ 9.8 $\times$4 = 1960 N
Total Mechanical energy = 1960 N
Kinetic energy when it is at fallen down 2 m = ?
Potential ​energy when it is at fallen down 2 m = mg(4-2) = 50$\times$ 9.8 $\times$2 = 980 N​
therefore, Kinetic energy when it is at fallen down 2 m = Total energy - potential energt at 2 m = 1960-980=980 N

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