Neutrons have a zero charge but consist of mass.
Answer:
r = 4.62 cm
Explanation:
Mass of a coffee, m = 370 g
Height of the mug, h = 5.5 cm
We need to find the inside radius of the mug. Density of an object is equal to the mass per unit volume. It can be given by :

So, the inside radius is 4.62 cm.
Answer:
P /K = 1,997 10⁻³⁶ s⁻¹
Explanation:
For this exercise let's start by finding the radiation emitted from the accelerator
= 
the radius of the orbit is the radius of the accelerator a = r = 0.530 m
let's calculate
\frac{dE}{dt} = [(1.6 10⁻¹⁹)² 0.530²] / [6π 8.85 10⁻¹² (3 108)³]
P= \frac{dE}{dt}= 1.597 10⁻⁵⁴ W
Now let's reduce the kinetic energy to SI units
K = 5.0 10⁶ eV (1.6 10⁻¹⁹ J / 1 eV) = 8.0 10⁻¹⁹ J
the fraction of energy emitted is
P / K = 1.597 10⁻⁵⁴ / 8.0 10⁻¹⁹
P /K = 1,997 10⁻³⁶ s⁻¹
To solve this problem we will apply the energy conservation theorem for which the work applied on a body must be equivalent to the kinetic energy of this (or vice versa) therefore


Here,
m = mass
= Velocity (Final and initial)
First case) When the particle goes from 10m/s to 20m/s



Second case) When the particle goes from 20m/s to 30m/s



As the mass of the particle is the same, we conclude that more energy is required in the second case than in the first, therefore the correct answer is A.