Question

At the start of an experiment, the potential energy of an object was 326 joules and its kinetic energy was 117 joules. At the end of the experiment, the potential energy of the object was 89 joules, and its kinetic energy was 331 joules. What conclusion can be drawn from this experiment? (1 point)
The total energy of the system increased due to the transfer of energy on a macroscopic scale to energy on a molecular scale.
The mechanical energy of the system decreased due to the transfer of energy on a macroscopic scale to energy on a molecular scale.
The mechanical energy of the system increased due to the transfer of energy on a macroscopic scale to energy on a molecular scale.
The total energy of the system decreased due to the transfer of energy on a macroscopic scale to energy on a molecular scale.

Answer 1

The mechanical energy decreased: initially 326 + 117 = 443 J, finally 89 + 331 = 420 J, a loss of 23 J — so mechanical energy was converted to molecular (thermal) energy.