What form of energy is changed to sound energy when uou use a cd player?
1 answer:
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<u>Answer:</u> The energy gained by the air molecules is 0.011 J.
<u>Explanation:</u>
Law of conservation of energy states that energy can neither be created nor be destroyed but it can only be transformed from one form to another form.
Here, the potential energy of the coffee filter is getting converted into kinetic energy of the coffee filter and some energy is lost by it which is gained by the air molecules in the form of kinetic energy.
So, calculating the potential energy of coffee filter, we use the equation:
P = mgh
where,
m = mass of coffee filter = 1.2 g = (Conversion used: 1 kg = 1000 g)
g = acceleration due to gravity =
h = height of coffee filter = 1 m
Putting values in above equation, we get:
- Calculating the kinetic energy of coffee filter, we use the equation:
where,
m = mass of coffee filter = 1.2 g =
v = speed of coffee filter = 0.8 m/s
Putting values in above equation, we get:
As, energy lost by coffee filter = energy gained by air molecules
So, energy lost by coffee filter = Potential energy - Kinetic energy
Energy lost by coffee filter =
Hence, the energy gained by the air molecules is 0.011 J.
Answer:
To obtain the power, we first need to find the work made by the force.
1) To calculate the work, we need the next equation:
So the force is given by the problem so our mission is to find 'dx' in terms of 't'
2) we know that:
So we have:
Then:
3) Finally, we replace everything:
After some calculation, we have as a result that the work is:
161.9638 J.
4) To calculate the power we need the next equation:
So
P = 161.9638/4.7 = 34.46 W