Final answer:
A heavier object will have more kinetic energy than a lighter object if both are moving at the same speed because kinetic energy is directly proportional to mass and velocity. A 2500 kg truck will have more kinetic energy than a 1500 kg car if they are traveling at the same speed. The truck would also use more fuel to maintain that speed due to its larger mass.
Step-by-step explanation:
A heavier object will have more kinetic energy if it is moving at the same speed as a lighter object. This is because kinetic energy (EK) depends on both the mass (m) and the velocity (v) of the object, as represented by the equation EK = 1/2 mv2. So, for example, a truck weighing 2000 kg traveling at 100 km/hr will have more kinetic energy than a car weighing 500 kg at the same speed. Additionally, comparing momentum and kinetic energy, an object with a small mass and high velocity can have the same momentum as a larger mass with lower velocity, but the object with the larger mass will have greater kinetic energy.
In the case of the 1500 kg car and the 2500 kg truck moving at the same speed, the truck will possess higher kinetic energy due to its greater mass. When considering fuel usage with potential energy being converted into kinetic energy, it logically follows that the truck will also use more gas to travel the same distance, because a greater amount of energy is required to move its larger mass at the same speed as the car.