Answer:
h = 16.67m
Explanation:
If the kinetic energy of the cylinder is 510J:


Where the inertia is given by:

Replacing this value:

Speed of the block will therefore be:

By conservation of energy:
Eo = Ef
Eo = 0

So,

Solving for h we get:
h=16.67m
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:

Explanation:
We must use conservation of linear momentum before and after the collision, 
Before the collision we have:

where these are the masses are initial velocities of both players.
After the collision we have:

since they clong together, acting as one body.
This means we have:

Or:

Which for our values is:

Answer:
Machines reduce the time of work hence reducing the rate of doing work ( power ).
Machines e.g pulleys carry heavy loads with a less and reasonable effort.
Machines e.g generators induce current in a limited amount of time