<h2>
Answer: The half-life of beryllium-15 is 400 times greater than the half-life of beryllium-13.</h2>
Explanation:
The half-life 
of a radioactive isotope refers to its decay period, which is the average lifetime of an atom before it disintegrates.
In this case, we are given the half life of two elements:
beryllium-13: 
beryllium-15: 
As we can see, the half-life of beryllium-15 is greater than the half-life of beryllium-13, but how great?
We can find it out by the following expression:
Where 
is the amount we want to find:
Finally:
Therefore:
The half-life of beryllium-15 is <u>400 times greater than</u> the half-life of beryllium-13.
<h3>Answer;</h3>
<em>B.)neither longitudinal nor transverse</em>
<h3><u>Explanation;</u></h3>
- <em><u>Longitudinal waves</u></em> are waves in which the vibration of particles is parallel to the direction of the wave motion.
- <em><u>Transverse waves</u></em> on the other hand are those waves in which the vibration of particles is perpendicular to the direction of the wave motion.
- In <em><u>surface waves particles in the medium of transmission move in a circular motion.</u></em> Therefore, they are neither transverse waves nor longitudinal waves.
Answer:
A. potential energy is 258720 Joule
Explanation:
A.Gravitational potential energy is: PE = m × g × h
velocity = 15.33 m/s when the car reaches the bottom of the hill.
where, m = mass
g = acceleration due to gravity
h = height from the bottom of hill.
The potential energy is : m×g×h
=(2200×9.8×12)
=258720 Joule
B. at the bottom of the hill, the potential energy is converted into kinetic energy so PE at top = KE at bottom
kinetic energy= 
(
)
where v = velocity
m= mass
therefore, v=
or, v=
or, v=15.33 m/s
As per above given data
initial velocity = 19.3 km/s
final velocity = - 18.8 km/s
now in order to find the change in velocity
Part b)
Now we need to find acceleration
acceleration is given by formula
given that
now the acceleration is given as
so above is the acceleration
Explanation:
Neutral carbon-12 (or any carbon atom) has 6 electrons with a total negative charge of 6e- orbiting a nucleus with a total positive charge of 6e+, so that the total net charge is zero. The nucleus is made up of 6 protons, each with a positive charge of e+, and 6 neutrons, each with zero charge.
