Final answer:
The potential energy of the baby carriage at the top of the hill is A) 252 Joules, calculated using the formula PE = Weight × Height, given that the weight is 12 Newtons and the height is 21 meters.
Step-by-step explanation:
The potential energy (PE) of an object at a height is calculated using the formula PE = mgh, where m is the mass, g is the acceleration due to gravity (typically 9.81 m/s²), and h is the height above the ground. However, since the weight of the baby carriage is already given in Newtons (which is the force due to gravity on the mass), we only need to multiply by the height to find the potential energy: PE = Weight × Height.
In this case, the weight of the carriage with the baby is 12 Newtons, and the height of the hill is 21 meters. Thus, the potential energy is PE = 12 N × 21 m = 252 Joules. Therefore, the answer is A. 252 J.