False, the spinning coil of wire that moves the cone in a speaker does not produces sound.
<u>Explanation</u>:
The wire coil is an electromagnet that is fixed to speaker cone. A normal magnet attached to the back of the speaker cone.When audio is sent in the form of short bursts of electric current to the speaker cone through the wire.
A magnetic field is induced when electric current allowed to pass through the coil. This magnetic field is repelled by the other magnet. This repulsion cause the cone to move forward. In the absence of electric current in the coil, the cone moves backward.
Thus sound waves are produced due to the resulting rarefaction and compression. So it is not the spinning coil of wire but he permanent magnet that produces the sound.
Answer:
8.35 × 
kg
Explanation:
Remember the formula for heat:
You just need to solve for m, doing so you're left with:
Replace the variables with numbers and that's it.
Answer:
E = 1440 kJ
Explanation:
It is given that,
Power of a cooker oven is 800 W
Voltage at which it is operated is 230 V
Time, t = 30 minutes = 1800 seconds
We need to find the electrical energy used by the cooker oven. The product of power and time is equal to the energy consumed. So,
So, electrical energy of 1440 kJ is consumed by the cooker oven.
Answer:
The instantaneous velocity is the specific rate of change of position (or displacement) with respect to time at a single point (x,t) , while average velocity is the average rate of change of position (or displacement) with respect to time over an interval.Average velocity : Average velocity of a body is defined as the change in position or displacement (Δx) divided by time interval (Δt) in which that displacement occurs.
Instantaneous velocity : The instantaneous velocity of a body is the velocity of the body at any instant of time or at any point of its path .
velocity can be positive , negative or zero.
By studying speed and velocity we come to the result that at any time interval average speed of an object is equal or more than the average but instantaneous speed is equal to instantaneous velocity.
Answer:
18,850 Hz
Explanation:
We need to figure out the wavelength of the sound wave.
Thus,
Wavelength = 1000 * Lowest Amplitude Wave
Wavelength = 1000 * 2.0 * 10^(-5)
Wavelength = 0.02
Or,
Now, we need the frequency of this wave. It goes by the formula:
Where
f is the frequency in Hz
v is the speed of sound in air (to be 377 m/s)
is the wavelength (we found to be 0.02)
Substituting, we find the frequency:
The wave has frequency of 18,850 Hz
