c) 101kPa
Hope I helped! ( Smiles )
Isotopes of an element will contain the same number of protons and electrons but will differ in the number of neutrons they contain. In other words, isotopes have the same atomic number because they are the same element but have a different atomic mass because they contain a different number of neutrons
A) d. 10T
When a charged particle moves at right angle to a uniform magnetic field, it experiences a force whose magnitude os given by

where q is the charge of the particle, v is the velocity, B is the strength of the magnetic field.
This force acts as a centripetal force, keeping the particle in a circular motion - so we can write

which can be rewritten as

The velocity can be rewritten as the ratio between the lenght of the circumference and the period of revolution (T):

So, we get:

We see that this the period of revolution is directly proportional to the mass of the particle: therefore, if the second particle is 10 times as massive, then its period will be 10 times longer.
B) 
The frequency of revolution of a particle in uniform circular motion is

where
f is the frequency
T is the period
We see that the frequency is inversely proportional to the period. Therefore, if the period of the more massive particle is 10 times that of the smaller particle:
T' = 10 T
Then its frequency of revolution will be:

I'm assuming the question is what is the robin's speed relative to to the ground...
Create an equation that describes its relative motion.
rVg = rVa + aVg
Substitute values.
rVg = 12 m/s [N] + 6.8 m/s [E]
Use vector addition.
| rVg | = √ | rVa |² + | aVg |²
| rVg | = √ 144 m²/s² + 46.24 m²/s²
| rVg | = √ 19<u>0</u>.24 m²/s²
| rVg | = 1<u>3</u>.78 m/s
Find direction.
tanФ = aVg / rVa
tanФ = 6.8 m/s / 12 m/s
Ф = 29°
Therefore, the velocity of the robin relative to the ground is 14 m/s [N29°E]
Sound waves.
Eathquake P-Waves