Answer:
8.4 m/s
Explanation:
The toy completes 10 circle in 30 seconds. So its frequency of revolution is

The periof of revolution is the reciprocal of the frequency, so

The radius of the circular path is
r = 4.0 m
So the total distance covered by the toy in one circle is the length of the circumference:

And so the average speed is

A ball falling through the air has a mass, a density, a volume...it is facing air resistance and is being acted on by gravity...it is accelerating and gaining velocity...and it is increasing in kinetic energy.
I suppose out of all those the biggest thing the ball has in this case is ENERGY. There are two main types to focus on...
Kinetic Energy - The further the ball fall the more KE it has...until terminal velocity is reach, then KE would become constant.
Potential Energy - Conversely to that of KE, the further the ball falls the less PE it will have.
<em>Heat/Thermal Energy is technically also present due to the friction from the air resistance, but the transfer of energy between the air and ball is quite complex and not necessary important for basic physics.
</em>
The question itself seem kind of vague and open ended, but I could just be viewing it the wrong way.
Comment if you need more help!
Answer:
The gain in velocity is 0.37m/s
Explanation:
We need solve this problem though the conservation of momentum. That is,


Using the equation to find
,

Using the conservation of energy equation, we have,




Now this energy over the cannonball



The gain in velocity is 0.37m/s
Auroras are frequently seen : B. After solar flares
The Aurora is created by an ongoing influx of particles into the Earth's existing magnetic field,
This particles originated from the Sun as part of Solar wind
hope this helps