To solve this problem it is necessary to apply the concepts related to the described wavelength through frequency and speed. Mathematically it can be expressed as:

Where,
Wavelength
f = Frequency
v = Velocity
Our values are given as,

Speed of sound
Keep in mind that we do not use the travel speed of the ambulance because we are in front of it. In case it approached or moved away we should use the concepts related to the Doppler effect:
Replacing we have,


Therefore the frequency that you hear if you are standing in from of the ambulance is 0.1214m
Answer:
Part a)

Part b)

Part c)

Part d)

Part e)

Part f)

Part g)

Explanation:
Initial speed of the launch is given as
initial speed = 
angle =
degree
Now the two components of the velocity

similarly we have

Part a)
Now we know that horizontal range is given as

maximum height is given as

so we have

time of flight is given as



Part b)
Now the speed of the ball in x direction is always constant
so at the peak of its path the speed of the ball is given as



Part c)
Initial vertical velocity is given as


Part d)
Initial speed is given as

so we will have


Part e)
Angle of projection is given as



Part f)
If we throw at same speed so that it reach maximum height
then the height will be given as


Part g)
For maximum range the angle should be 45 degree
so maximum range is


Answer:
The smallest radius will be four (4) times the initial radius
Explanation:
The car maintains a constant angular speed. According to Newton's Second Law F = m a
1. 
2. 
Replacing 2 in 1
3. 
Where:
Fr= Frictional force
Rp= Initial Radius
An= Centripetal Acceleration
M= Mass
V= Velocity
Also we have that:
4. 
μ= Coefficient of friction between the car and the surface
M= Mass
W= Weight
G= Gravity
r is cleared from equation 3
5. 
Replacing 4 in 5
6. 
Simplifying
7. 
Now we have a new velocity equal to twice the initial velocity, We replace it by 2v in equation 7
8. 
Computing
9. 
Replacing 5 in 9

Answer: 100 N
Explanation: Taking into account the second Newton Law the total force applied to any system is equal to the mass *acceleration.In this case the crate moves at constant speed so the accelaration is zero. In order to satisfy this fact, the friction force must be equal the applied force of 100 N .