Answer:

Explanation:
Assuming uniform spread of sound with no significant reflections or absorption. We know that sound intensity varies
where r is the distance
Since intensity is given then when at 3 m


Since we have the constant then at 4m
Intensity, 
Answer:
Acceleration: 
Explanation:
The acceleration of an object is equal to the rate of change of velocity:

where
u is the initial velocity
v is the final velocity
t is the time taken for the velocity to change from u to v
For the space probe in this problem, we have:
u = 100 ft/s (initial velocity)
v = 5000 ft/s (final velocity)
t = 0.5 s (time taken)
Therefore, the acceleration is

Answer
given,
time of disk stayed a loft = 16.7 sec
height reached = 18.4 m
mass = 72 kg
now work done is equal to change in potential energy



W = 12983.04 J
Positive sign means that work is in the direction of motion.



P = 777.42 Watts
The following apply:
Sound is a LONGITUDINAL wave.
Sound is a PRESSURE wave.
Longitudinal waves are waves in which the displacement of the medium is in the same direction as or opposite direction to the direction of wave propagation. An example of longitudinal wave is sound wave. Sound wave is also considered as a pressure wave as the result of the presence of repeating patterns of high and low pressure regions moving through a medium.
Answer:
Graph #2
Explanation:
Notice, on the position time graph, there is a constant rate of change. This means that there is a constant velocity, meaning it's a straight line. The line is decreasing so the velocity will be negative.