Electrons have a negative charge, so if you give away electrons, you give away negative charge, thus ending with a positive charge.
Answer:
Answer 2 is iron.
Answer 3 is magnetic induction.
Explanation:
I hope it's helpful!
The force the box is exerting on Manuel is the weight of the box, downward:

and this force is perfectly balanced by the constraint reaction applied by Manuel's hand, pushing upward.
Answer:
a) the total circle of "initial" is Epot./Eel. and the total circle of "final" is Ekin.
b)intia: 0.5 * 50 * 4^2 = 400 J
final: 0 J = 0.5 * 50 * 0^2
Explanation:
c) in the initial phase the spring is compressed and so has Epot but then the Energie changes to be totally Ekin (in final phase) and so the Epot becomes 0
change in momentum of car is given as

here we have

given that
m = 2000 kg


now we have

