Answer:

Given:
Temperature, T = 3.13 K
molar mass of molecular hydrogen, m = 2.02 g/mol = 
Solution:
To calculate the root mean squarer or rms speed of hydrogen molecule, we use the given formula:

where
R = rydberg's constant = 8.314 J/mol-K
Putting the values in the above formula:


Answer:
a) The velocity of the car is 7.02 m/s and the car is approaching to the police car as the frequency of the police car is increasing.
b) The frequency is 1404.08 Hz
Explanation:
If the police car is a stationary source, the frequency is:
(eq. 1)
fs = frequency of police car = 1200 Hz
fa = frequency of moving car as listener
v = speed of sound of air
vc = speed of moving car
If the police car is a stationary observer, the frequency is:
(eq. 2)
Now,
fL = frequecy police car receives
fs = frequency police car as observer
a) The velocity of car is from eq. 2:

b) Substitute eq. 1 in eq. 2:

C) a solid lower part and a liquid upper part
Explanation:
The physical nature of the earth's core is made up of a solid lower part and a liquid upper part.
The core is the innermost part of the earth and it is made up of metallic minerals.
- It has the highest temperature and pressure of all the layers of the earth.
- The core is divided into two. Outer and inner core.
- Outer core is made up of molten metallic minerals. It is the layer where the earth geomagnetic field originates.
- The inner core is solid metallic ball.
- Evidence from seismic waves has furnished geoscientists with this knowledge.
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Explanation:
Liquids also exert pressure in all directions on the walls of the container they are stored in. We see water coming out from leaking pipes and taps. ... Gases (Air) also exert pressure in all directions