The answer for this question is, it was attempting to make the motor cycle safe
Answer:
The correct answer is option 'd': The frequency decreases and the intensity of the sound decreases.
Explanation:
1) <u>Effect on Frequency </u>
According to Doppler's effect of sound we have
for a source of sound moving away from the observer the relation between the observed and the original frequency is given by

where
c = speed of sound in air
is the velocity of observer of sound
is the velocity of source of sound
is the original frequency of sound
As we see the ratio is less than 1 thus the frequency of sound that the observer receives is less than that of source.
2) <u>Effect on Intensity:</u>
At a distance 'r' from source emitting a wave of Power 'P' is given by

As we see on increasing 'r' intensity of sound decreases.
Answer:
As the car travels up the coaster it is gaining potential energy.
Explanation:
Because It has the greatest in amount of potential energy at the top of the coaster. when the car travels down the roller coaster it obtains speed and kinetic energy.
This is amazing. When you read the quest ion, you wouldn't think there's enough information there to find an answer. But there is !
-- When the block is sliding along the flat surface, its kinetic energy is (1/2)(Mass·v²).
-- When it's 2.5m up the ramp and stops, its potential energy is (2.5m)·(Mass·g).
-- If there's no friction anywhere, these energies are equal.
(1/2)(Mass·v²) = (2.5m)·(Mass·g)
(v²/2) = (2.5m) · g
v² = 5m · g
v² = 49 m²/s²
<em>v = 7 m/s </em>(B)
Friction is an example of thermal energy. As the tiny heat particles move, more warmness is made from the friction.