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:

Explanation:
Let say the empty wagon has mass "M"
now by newton's II Law we will have

now it is given that empty wagon is pulled with acceleration 1.4 m/s/s
now we will have

now a child of mass three times the mass of wagon is sitting on the empty wagon
so here we have


so we have

Answer:
Objective: It is raining. Subjective: I love the rain!
Explanation:
Anything objective sticks to the facts, but anything subjective has feelings. Objective and subjective are opposites.
(Hope this helps can I pls have brainlist (crown)☺️)