I believe the answer is D. Thunderstorm
Unstable air indicates that <span>the lowest layers of an </span>air<span> mass is low in temperature. Thunderstorms is more likely to happen if there is unstable air mass because it provide a situation where there is more energy for the Thunderstorms to feed off of.</span>
Answer:
v = 7.95 m/s
Explanation:
Given that,
Wavelength of a wave, 
Frequency of a wave, f = 15 Hz
We need to find the speed of the wave. The speed of a wave is given by :

So, the wave move with a speed of 7.95 m/s.
Answer:
~~Now, you have left your question very open ended and didn't ask for any particular kind of answer so I'll do my best to get what you're looking for.~~
A physical change in a substance doesn't change what the substance is. It can possibly melt or freeze an object. I mean heat makes things expand while cooling makes them retract.... In chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed.
Answer:
The magnitude of the resultant of the magnetic field is 
Explanation:
Given that,
Current = 40 A
Magnetic field 
Distance = 22 cm
We need to calculate the magnetic field
Using formula of magnetic field

Where, r = distance
I = current
Put the value into the formula


We need to calculate the magnitude of the resultant of the magnetic field
Using formula of resultant

Put the value into the formula


Hence, The magnitude of the resultant of the magnetic field is 