Answer:
The time taken is 
Explanation:
From the question we are told that
The speed of first car is 
The speed of second car is 
The initial distance of separation is 
The distance covered by first car is mathematically represented as

Here
is the initial distance which is 0 m/s
and
is the final distance covered which is evaluated as
So


The distance covered by second car is mathematically represented as

Here
is the initial distance which is 119 m
and
is the final distance covered which is evaluated as

Given that the two car are now in the same position we have that


The lower the frequency the lower the pitch sound.
The amount of heat needed to increase the temperature of a substance by

is given by

where
m is the mass of the substance

the specific heat capacity

the increase in temperature
In our problem, the mass of the water is m=750 g, the specific heat is

and the amount of heat supplied is

, so if we re-arrange the previous formula we find the increase in temperature of the water:
Acceleration a=3m/s^2
time t= 4.1seconds
Final velocity V= 55km/h
initial velocity U= ?
First convert V to m/s
36km/h=10m/s
55km/h= 55*10/36=15.28m/s
Using the formula V= U+at
U= V-at
U= 15.28-3*4.1=15.28-12.3=2.98m/s
Initial velocity U= 2.98m/s or 10.73km/h (Using the conversion rate 36km/h=10m/s)