Final answer:
A tower crane's primary function is to hoist heavy objects, especially during construction, by applying force over a distance to lift materials. It performs work through different phases of lifting, and the principles governing its operation differ from horizontal pushing due to involvement of different forces at play.
Step-by-step explanation:
The purpose of a tower crane is to hoist heavy objects. It is used extensively on construction sites to lift and place heavy materials such as sandstone beams high above the ground. This allows construction at various heights which is essential for building tall structures. To illustrate, during historical times, cranes like the Castello, with a wooden mast and controlled by screws and counterweights, were used to hoist materials with efficiency, saving time and money.
In the context of physics, when a crane lifts construction materials, it performs work on them by applying a force over a distance. For instance, when a crane lifts materials to a height of 60 meters, with varying force over different sections of the lift, the total work done can be calculated by integrating the force over the distance covered. This involves calculation of the areas under the force-distance graph, which represents the work done during acceleration, constant force, and deceleration phases.
When comparing the actions of lifting an object with a crane and pushing it across a rough surface, both begin and end at rest due to the principles of mechanics. However, they operate under different conditions: a crane lifts vertically overcoming gravitational force while pushing on a rough surface involves overcoming frictional force horizontally.