Answer:
a) 20.29N
b) 19.43N
c) 15N
Explanation:
To find the magnitude of the resultant vectors you first calculate the components of the vector for the angle in between them, next, you sum the x and y component, and finally, you calculate the magnitude.
In all these calculations you can asume that one of the vectors coincides with the x-axis.
a)

b)

c)

Answer: h = 3.34 m
Explanation:
If the hat is thrown straight up, then at its highest point it has no motion and no kinetic energy. All energy is potential energy
PE = mgh
h = PE/mg = 4.92 / (0.150(9.81)) = 3.34352... ≈3.34 m
Answer:
B) protons and neutrons.
Explanation:
The protons and neutrons are located in the nucleus of the atom and represent most of the 'mass' of the atom, that's their count that determine the 'mass' of an atom (like 12 for Carbon).
The electrons rotate around the nucleus and have a negligible mass.