Final answer:
The potential energy of the boulder is 132,300 J.
Step-by-step explanation:
The potential energy of an object is given by the equation PE = mgh, where m is the mass of the object, g is the acceleration due to gravity, and h is the height of the object above a reference point. In this case, the boulder has a mass of 150 kg and is sitting on a cliff that is 90 m high. Plugging these values into the equation, the potential energy of the boulder is:
PE = (150 kg)(9.8 m/s^2)(90 m) = 132,300 J
Therefore, the correct answer is
A. 13,500 J