To develop this problem we will apply the concepts related to the Doppler effect. The frequency of sound perceive by observer changes from source emitting the sound. The frequency received by observer 
is more than the frequency emitted by the source. The expression to find the frequency received by the person is,
= Frequency of the source
= Speed of sound
= Speed of source
The velocity of the ambulance is
Replacing at the expression to frequency of observer we have,
Therefore the frequency receive by observer is 878Hz
Answer:
Alfred Wegener proposed the idea that earths lithospher is divided into tectonic plates.The theory was only accepted after he died.
An object is in motion if its distance from another object is changing. An object is in motion if it changes position relative to a reference point. An reference point is a place or object used for comparison to determine if something is moving.
It’s c because it’s not Control so that means that it would be broken and non fix able
Answer:
mechanical energy
Explanation:
In an electric motor the electrical energy is converted into mechanical energy. Almost every mechanical movement that we see around us is accomplished by an electric motor. Electric machines are a means of converting energy. Motors take electrical energy and produce mechanical energy.
