A book is sitting on a table, which is sitting on the Earth. The book has a weight of 10 N and the
table has a weight of 20 N as labeled on the diagram.
a. Find all contact forces, F12. (For example, “FEB” would mean “Force of Earth ON
b. Next to each, tell me which of Newton’s laws allowed you to make your
conclusion. (2nd or 3rd)
The Attempt at a Solution
New to free body diagrams. I think I was able to name the contact forces for this concept problem.
F(bt) downward F(tb) upward. This would be an example of the third law.
F(te) downward F(et) upward. Also an example of the law.
If W(b) downward is 10 N then F(tb) upward = 10 N also
If W(t) downward is 20N, then F(bt) downward is 10N, which should make F(et) = 30N