If you look at a atom under a electron microscope you would use it
your answer is the letter (b)
Answer:

Explanation:
The electric potential energy is the potential energy that results from the Coulomb force and is associated with the configuration of two or more charges. For an electron in the presence of an electric field produced by a proton, the electric potential energy is defined as:

where
is the electron charge,
is the proton charge, r is the separation distance between the charges and k is the coulomb constant.
Knowing this, we can calculate how much electric potential energy was lost:

Answer:
A. 500 N
Explanation:
Acceleration is change in velocity over change in time.
a = Δv / Δt
a = (50 m/s − 20 m/s) / 3 s
a = 10 m/s²
Force is mass times acceleration.
F = ma
F = (50 kg) (10 m/s²)
F = 500 N
Answer:
4.3 m/s
Explanation:
Using conservation of momentum, assume that the collision is elastic and that the 3.0 g ball stuck with the carton
3.0 g = 3 / 1000 = 0.003 kg = m₁
40 g = 40 / 1000 = 0.04 kg = m₂, u₂ = 0 since the body is stationary and v = 0.3m/s
m₁u₁ + m₂u₂ = v ( m₁ + m₂)
0.003 u₁ = 0.30 ( 0.003 + 0.04) = 0.0129
u₁ = 0.0129 / 0.003 = 4.3 m/s