Answer:
the frequency of the hummingbird is 80 Hz.
Explanation:
Given;
number of times the hummingbird beats its wings, n = 4,800 times
the duration of this motion, t = 1 minute
The frequency of the hummingbird wings is calculated as follows;
Therefore, the frequency of the hummingbird is 80 Hz.
Answer: The symbol representing the result of a gas expanding against a constant pressure is W
Explanation:
According to first law of thermodynamics, energy can neither be destroyed nor created but rather transferred to one place to another and converted to and from other energy forms.
The mathematical form of first law of thermodynamics is:
where = change in internal energy
q = heat absorbed or released
W = work
P = pressure
= volume change
Thus the changes in heat or work leads to change in internal energy.
Answer:
Change in mechanical energy,
Explanation:
It is given that,
Mass of the projectile, m = 12 kg
Speed of the projectile, v = 20 m/s
Maximum height, h = 18 m
Initially, the projectile have only kinetic energy. it is given by :
K = 2400 J
Finally, it have only potential energy. it is given by :
P = mgh
P =2116.8 J
The change in mechanical energy is given by :
So, the change in mechanical energy is 283.2 J. Hence, this is the required solution.