<span>Mass of the copper penny m = 2.6 g
Atomic mass of copper = 63.55, Atomic number = 29,
So the number of neutrons = Atomic mass - Atomic number = 63 - 29 = 34
a. Neutron mass = 34 x (2.6 / 63.55) = 1.4 grams
Copper atoms per mole = 6.040 x 10^23 atoms/mol
moles of copper = 2.6 / 63.06 = 0.04123 mol
Total atoms in the copper = 6.040 x 10^23 atoms/mol x 0.04123 mol = 0.25 x 10^23 atoms
Number of electrons in the copper = 29 per atom
Mass of the electron = 9.085 x 10^-28 g
b. Electron mass = 0.25 x 10^23 x 29 x 9.085 x 10^-28 = 65.86 x 10^-5 g</span>
Answer:
F1 = K Q1 Q2 / R1^2
F2 = K Q1 / 2 * Q2 / (2 R1)^2
F2 / F1 = 1/2 / 4 = 1/8
The new force is 5N (1/2 due to charge and 1/4 due to distance)
Define unit vectors as follows:

is in the eastern direction.

is in the northern direction.
The position of the first bird is

The position of the second bird is

Let θ = the angle between the net displacement vector for the two birds.
By definition,



Similarly,
|b| = 4.025
Therefore

Answer: 36.9°
Answer:
A
Explanation:
I only think its A because of the gravity part...sorry im not good at explaining
Answer:
maybe its heat sorry if it's wrong
because if friction is not in the problem so we are making heat or thermal energy