<span>Charging by friction occurs, Electrons are transferred when one object rubs against another.
Another example of this would be socks on carpet.
Hope this helps!</span>
I found the Hydrolic system, im not sire if its helpful or not. I could only find that one, sorry if it doesn't help but I hope it does ^-^
Answer:
a.
b. 
Explanation:
<u>Given:</u>
- Velocity of the particle, v(t) = 3 cos(mt) = 3 cos (0.5t) .
<h2>
(a):</h2>
The acceleration of the particle at a time is defined as the rate of change of velocity of the particle at that time.

At time t = 3 seconds,

<u>Note</u>:<em> The arguments of the sine is calculated in unit of radian and not in degree.</em>
<h2>
(b):</h2>
The velocity of the particle at some is defined as the rate of change of the position of the particle.

For the time interval of 2 seconds,

The term of the left is the displacement of the particle in time interval of 2 seconds, therefore,

It is the displacement of the particle in 2 seconds.
the answer is c because it is the 3rd step in the scientific analysis steps