The contact force is indeed caused by "Contact".
Air resistance is basically a type of friction, which is apparently present providing two object contact.
The rest selections are all interaction force, which is not necessarily caused by contact.
Answer: v = 
Explanation: q = magnitude of electronic charge = 
mass of an electronic charge = 
V= potential difference = 4V
v = velocity of electron
by using the work- energy theorem which states that the kinetic energy of the the electron must equal the work done use in accelerating the electron.
kinetic energy = 
, potential energy = qV
hence, 
Answer:
15.5 seconds
Explanation:
Apply Newton's second law:
∑F = ma
-12500 + 9200 = (12000) a
a = -0.275 m/s²
v = at + v₀
0 = (-0.275) t + 4.25
t = 15.5 s
It takes the boat 15.5 seconds to stop.
Almost right. protons are positive and electrons are negative. so when you run the balloon on your hair, electrons are transferred between them (i’m not sure which direction) and now one is positively charged as it lost negative particles and one is negative as it gained negative particles (electrons). opposite charges attract
