The frequency of a sound is whatever frequency leaves the source. It doesn't change.
Voiced of swimmers at the pool don't change frequency in or out of the water. Only their speed and wavelength change.
Answer:
Explanation:
The general equation for the disk with moment of inertia I when given small angular displacement
is given by

Replacing

where
is the angular frequency of oscillation
General solution for this Equation is given by

where 

Thus K can be written as

The correct answer is 17.24 m/s. You get the answer by subtracting the two heights of the tracks which are 36.5 and 10.8 m, and the answer is 25.7. Since you already know the height at which the kinetic energy will be coming from, you then divide the amount of weight the roller coaster has to the distance it needs to travel in order for you to determine the speed of the car. So that is, 4,357 kg and 25.7 m and the answer is 169 kg/m. Dividing it to the earth's gravity of 9.8 m/s you'll get 17.24 m/s.
First, we get the difference between the kinetic energies such that,
difference = (220J - 120J)
difference = 100 J
The difference in kinetic energy is the equivalent of the potential energy which is calculated through the equation,
PE = mgh
To calculate for the height, we derive the equation in a form,
h = PE/mg
The product of the mass and acceleration due to gravity is the weight.
h = (100 J) / (5 N)
h = 20 m
<em>Hence, the answer is 20 m. </em>