PHY 1010 – Chapter 4 Activity: Forces

1. Slides 33 – 35 of the PowerPoint describes Newton’s Law of Universal Gravitation:

where is the universal gravitational constant. Considering that on Earth you are subject to the acceleration of gravity , and , where is your mass in ,

where and are the mass and radius of the Earth, respectively. If you weigh as much on the Moon, calculate the mass of the Moon using the radius of the Moon , and vice versa. Check your calculated values against their knowns, how close are they to one another? Is it a good estimate to say you weigh as much on the Moon? You can find the values of , , , and on this NASA reference page:

https://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html

2. Calculate the net force & acceleration (with direction!) on the object in the diagram below:

3. Draw a free body diagram depicting the various forces at play in these static systems:

a. Mass & pulley system on a frictionless inclined plane:

b. Gondola lift:

c. Mass on an inclined plane (with friction):