Answer:
The tangential velocity of a rotating object is:
v = r*w
where r is the radius, and w is the angular velocity.
w = 2*pi*f
where f is the frequency.
We know that the record plater does 11 revolutions in 20 seconds, then it does:
11 rev/20s = 0.55 rev/s = f
then we have:
w = 2*pi*0.55 s^-1 = 2*3.14*0.55 s^-1 = 3.454 s^-1
The radius of a record player is really variable, it is around 10 inches, so i will use r = 10in, which is the rotating part of the record player.
then the tangential velocity is:
v = 10in*3.454 s^-1 = 34.54 in/s
I would say clay, because its a solid
Answer:
Sleeping, since your brain is working, but your physical body is not moving at all or moving rarely, therefore there is no work done in the activity of sleeping.
Explanation:
The difference between velocity and relative velocity is that velocity is measured with respect to a reference point which is relative to a different point. While relative velocity is measured in a frame where an object is either at rest or moving with respect to the absolute frame.
To solve this problem we will apply the concepts related to the Doppler Effect, defined as the change in apparent frequency of a wave produced by the relative movement of the source with respect to its observer. Mathematically it can be written as
Here,
= Frequency of the source
= Speed of the sound
= Speed of source
Now the velocity we have that
Then replacing our values,
Therefore the frequency of the observer is 1047.86Hz
