Answer:
Contact forces are forces that require the actual contact (touching) of two pieces of matter. There are a variety of contact forces. A very common one is friction. Anytime that two surfaces are in contact with one another, there is friction between the two surfaces. A field force is a force that works at a distance. No touching is required. Gravity is a good example of a field force, because it works whether or not an object is touching something or touching nothing at all.
Complete Question
The complete question is is shown on the first uploaded
Answer:
The elastic potential energy at point B is
The kinetic energy at point D is
Explanation:
Looking at the given point we can observe that mechanically energy(i.e potential and kinetic energy ) is conserved and it value is
So at point B
KE at point B is 50J
So
Now at point D
at point D is 25J
So
The answers I got was D and B