Answer: D
Explanation: Energy is neither created nor destroyed so the amount of reactants and products must be equal
I think its b but not sure
when observer and source moves relative to each other then the frequency received by the observer is different from the real frequency
This apparent change in frequency due to relative motion is known as Doppler's effect.
Here we know that

here we know that
= real frequency
v = speed of sound
= speed of observer
= speed of source
so this is known as Doppler's Effect
The angular velocity is defined as "the angle changing over time."
From the given of the problem:
m = 100g
rate of revolution = 50 rev / min
Therefore, using the formula:
angular velocity = rate of revolution x 2*pi / revolution
Substituting:
angular velocity = (50 revs / min) x ( 2*pi radians / rev ) = 100*pi radians / min
As you can see, mass is not a part of the equation for solving the angular velocity therefore the amount of mass does not affect its value.
1. What is the skydiver's acceleration?
Initially, like any falling object, a skydiver's downward acceleration is 9.8 meters/seconds^2, or about 28-35 feet per second squared. This acceleration reduces over a few seconds and approaches zero as the skydiver reaches terminal velocity.