Answer:
Explanation:
Given
height of grand canyon is 
Rock is dropped i.e. initial velocity is zero

Using Equation of motion

h=height
u=initial velocity
a=acceleration
t=time
here a=acceleration due to gravity


<h2>Answer: free electrons</h2>
<u>Plasma</u> is known as the 4th state of matter and is itself ionized gas. In this sense, ionization consists of the production of ions, which are <u>electrically charged atoms or molecules due to</u><u> the excess or lack of electrons</u><u> with respect to a neutral atom or molecule.
</u>
That is why in this process there are always<u> free electrons</u>. Therefore in heating gas to create plasma can yield free electrons, and the correct option is D.
Answer:
Explanation:
The rate of change in volume is proportional to the surface area:
dV/dt = kA
Integrating:
V = kAt + C
At t=0, V = s, so:
s = kA(0) + C
C = s
Therefore:
V = kAt + s
First, convert all the km/hr into m/s
You will get that
initial speed = 20 m/s
Initial speed of Green train = 40 m/s
Initial separation = 950 m
Velocity of approach = 20 - -40 = 60 m/s
relative acceleration = -4 m/s^2
v = u + at
0 = 60 - 4t
t = 15s
s = ut + 1/2 *at * t
s = 60 * 15 - 1/2 *4 * 225
s = 900 - 450
Separation when they stop = 450 m
hope this helps