Cavendish's Lab Questions

One of the oldest questions in history is why and how fast do things fall to the Earth? This was not far from Henry Cavendish’s goal. In 1798 Cavendish sought to find the density of the Earth which in turn can be used to calculate the weight of the world. His experiment however required him to calculate an undefined variable in Newton’s law of universal gravitation known as G or the gravitational constant. Cavendish through his experiment discovered that the Earth’s gravitational constant was 9.8 m/s^2. Cavendish’s experiment made use of two lead spheres connected by a horizontal wooden rod suspended by a thin metal string. His final calculation of Earth’s density was 5.48 times that of water which is only .04 off of today’s accepted value of 5.52 times the density of water.
Cavendish’s experiment was the first time anyone had addressed Newton’s G from Newton’s law of universal gravitation.
Even though finding G was not Cavendish’s primary objective he gave us an answer to the physical phenomenon that is gravity. Before this time many had questioned why things fell to towards the Earth and Aristotle even claimed that heavier objects feel faster than lighter ones, something that Cavendish could now prove scientifically was wrong. Cavendish’s measurement of gravity allowed physicist and average civilians alike to understand with a little background information that acceleration due to gravity on earth is consistent. It also explained why two similar shaped objects with different weights fell at the same rate as proven, but not explained, by Galileo many years before. Cavendish was inadvertently supporting the ideas of other great experiments by finding the Gravitational
constant.
Now knowing what we know about Cavendish’s experiment we can conclude that his findings were revolutionary in the field of physics. Finding the gravitational constant allows physics students to calculate projectile motion, the gravitational pull between two objects, velocity of objects in freefall and many other values. Gravity equations are something that most students of Physics 1001 make use of every day in class. However, the uses do not stop there after having learned these gravity equations we can make use of them in our daily lives as well as jobs. Whether we decide to become high rise welders or doctors we all have to at some point or another overcome the forces of gravity and with an understanding of the why and how gravity works allows us to calculate how much force a patient would experience if they were to fall out of their bed or off a structure and knowing this can help doctors understand what type of damage the patient has sustained from impact and allows them to treat their patients more effectively and quickly. In the case of a high rise welder, understanding the force of impact a specific tool falling a certain height, can make them more conscientious of where they set their tools and who is below them. All and all I think anyone who has taken a course in physics would agree that the gravitational constant that Cavendish calculated back in 1798 plays a pivotal role in today’s understating of physics.