The first egg is thrown at a wall and breaks because it has no time to decelerate and it breaks.
While, when a second egg is thrown at wall with same velocity and collides with a bed sheet, it does not break because it get more time to decelerate or collide with the wall. It reduces the amount of force exerted on the egg and it does not break.
The maximum is 1800 J since energy is not created nor destroyed, it is just transformed. In this example, gravitational potential energy is transformed to kinetic energy.
The answer to your question is "A. a lower frequency of the siren.
Because the person in back of the ambulance will hear a lower frequency of the siren. This is because the waves are stretched out. A longer wavelength results in a lower frequency.
