in Melbourne there used to be a huge shopping centre called "diamaru" built around an old "shot tower". hot lead globules were poured from the top of the tower which fell into a large pool of water at the foot of the tower. in this way spherical lead shot was made; hence the name.
why does the lead form into spherical globules in this process?
and what's one assumption you made which is probably in error and would result in a shorter tower for the iron ball bearing scenario?
someone help please!!thankyou soo much!
I would think on the ratio of air resistance to weight. Air resistance tends to flatten the sphere, slow it down.
Of course, cohesion is the binding force that makes the sphere, and in a zero gravity (or free fall), the mass would assume a sphere shape.
To understand why lead forms into spherical globules in the process described, let's consider the forces at play. The primary force acting on the molten lead as it falls from the top of the tower is gravity, which pulls the lead downward. As the lead falls, it experiences resistance from the air. This resistance, known as air drag or air resistance, can affect the shape of the falling material.
When a molten metal such as lead falls through the air, the air drag tries to flatten it. However, lead possesses unique properties that allow it to resist deformation and maintain its spherical shape. Lead has a high surface tension, which is the force that holds the molecules of a liquid together and minimizes its surface area. As the molten lead falls through the air, its surface tension helps it to form into spherical globules.
The combination of gravity pulling the lead downward and the lead's own surface tension working against the air drag results in the formation of spherical lead shot. The molten lead is able to maintain its shape as it falls and solidifies, creating perfectly round spheres that then collect in the pool of water at the foot of the tower.
Regarding the assumption of a shorter tower for the iron ball bearing scenario, one potential error could be the assumption that air resistance would not significantly affect the shape of the iron ball bearings as they fall. Unlike molten lead, solid ball bearings do not possess the same surface tension and fluid-like behavior. As a result, air resistance could have a more pronounced effect on the shape of the falling ball bearings, potentially causing them to deform or flatten more easily. This could lead to a shorter tower being required in order to achieve the desired spherical shape.