Answer: The frequency heard is 562.7 Hz.
Explanation: <u>Doppler</u> <u>Effect</u> happens when there is shift in frequency during a realtive motion between a source and the observer of that source.
It can be calculated as:
where:
c is the speed of light (c = 332m/s)
all the subscripted s is related to the Source (frequency, velocity);
all the subscripted o is related to the Observer (frequency, velocity);
As the source is moving towards the observer and the observer is moving towards the source, the velocities of each are opposite related to direction.
So, the frequency perceived by the observer:
= 562.7 Hz
At this condition, the observer hears the train's horn in a perceived frequency of 562.7 Hz
<u>Answer:</u>
<u>Explanation:</u>
Given data,
- mass of the crate, m = 200 kg
- height of the shipping container, h = 45 m
- gravitational of a body is possessed by the body due to the virtue of its position.
The formula for gravitational potential energy is,
P.E = mgh joules
Substituting the values
P.E = 200 x 9.8 x 45
= 88,200 J
Hence, the <u>gravitational potential energy</u> of the crate <u>is, P.E = 88,200 J</u>
Because any other radiation can be harmful<span />
During convection of air currents, cool air sinks. <em>(b)</em>