Answer:
The radius of the disc is 2.098 m.
(e) is correct option.
Explanation:
Given that,
Moment of inertia I = 12100 kg-m²
Mass of disc m = 5500 kg
Moment of inertia :
The moment of inertia is equal to the product of the mass and square of the radius.
The moment of inertia of the disc is given by

Where, m = mass of disc
r = radius of the disc
Put the value into the formula



Hence, The radius of the disc is 2.098 m.
Answer:
The prediction for its maximum potential energy is 109,375 J
Explanation:
Given;
mass of the coaster car, m = 350 kg
speed of the coaster car at the lowest point, v = 25 m/s
The coaster car will have maximum kinetic energy at the lowest point and based on law of conservation of mechanical energy, the maximum kinetic energy of the coaster car at the lowest point will be equal to maximum potential energy at the highest point.



Therefore, the prediction for its maximum potential energy is 109,375 J
The physical law that explains that is the law of conservation of energy which states that he energy of an isolated sistem remains constant