Answer:
0.29713 m/s
Explanation:
m = Mass of person
g = Acceleration due to gravity = 9.81 m/s²
v = Velocity
r = Radius = 18 mm
By balancing the forces in the system we have

The velocity of the coaster is 0.29713 m/s
Electromagnetic waves do not require a medium to travel through. They can travel through empty space or matter.
Answer:
The second trumpeter will be playing at frequency = 515 Hz
Explanation: Given that the note sounds lower and they can hear 20 beats in 4.0 s.
Beat frequency = 20/4 = 5 Hz
Beat frequency = F2 - F1
5 = 520 - F1
F1 = 520 - 5
F1 = 515 Hz
Since the note sound lower, the second trumpeter will be playing at 515 Hz frequency