Final answer:
In physics, when a truck moves from the top of a hill to the bottom, its potential energy is converted into kinetic energy. Safety precautions for an unattended lift truck include lowering the forks to the ground, applying the parking brake, and removing the keys if it's left unattended.
Step-by-step explanation:
When a lift truck is left unattended, certain safety precautions must be taken to ensure it is left in a safe manner to prevent accidents or damage. Similarly, in physics-related scenarios such as the one where a truck of mass 1.2 tons is parked at the top of a hill, concepts like potential energy, kinetic energy, and safety measures in physics are considered.
The question relates to the movement of the truck as it rolls down the hill. As the truck descends, the potential energy due to its position at the top of the hill is converted into kinetic energy. To quantify this transformation, the equation for potential energy (PE = mgh), where m is mass, g is the acceleration due to gravity, and h is the height, can be used. The initial potential energy can be calculated as the truck starts at the top of the hill.
When discussing the safety of a stationary lift truck, the forks must be in a position that minimizes the risk of tripping or collision. Generally, the forks should be lowered to the ground, the parking brake should be applied, and the keys should be removed if the operator is more than 25 feet away or the truck is out of sight. These measures ensure that the truck remains stationary and is not a hazard to others.
Understanding potential and kinetic energy in physics, and implementing proper safety precautions both relate to ensuring stability and minimizing the risk of undesired outcomes when dealing with heavy equipment such as lift trucks or when analyzing moving vehicles.