The sound is increased because sound waves are in fact mech. waves which means the that they can't travel through empty space and thus need a medium to travel through
Complete Question
The complete question is shown on the first uploaded image
Answer:
The value is 
Explanation:
Looking at the graph in the diagram we see each unit is equal to 1 both in the x axis and in the y- axis
Now the value of B along the x axis is

and along the y axis the value is

Hence the vector B is

Fnet=ma so m = fnet/a 100/5=20 the mass is 20
The change in the kinetic energy refers to the work done in displacing a body, thus, the change in the kinetic energy of an object refers to the work done on the object.
The correct formula to use is:
W = Initial kinetic energy - Final kinetic energy;
Where, W = change in kinetic energy
Final kinetic energy and initial kinetic energy = 1/2 MV^2
Initial velocity = 15 m/s
Final velocity = 13.5 m/s
Initial mass = 0.650 kg
Final mass = 0.950 kg
W = 1/2 [0.650* (15 *15)] - 1/2 [0.950 * (13.5 * 13.5)]
W = 146.25 - 173.13 = 26.88
Therefore, the change in kinetic energy is 26.88 J.
The negative sign has to be ignored, because change in kinetic energy can not be negative.
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The answer is apogee my dude