It is called a dotted half note.


Given :


We, have to find frequency :





Hope Helps!
<span>At first when the car is at the datum
point where is no elevation, the kinetic energy increases while the potential
energy is zero. As it travel the path and goes upward the kinetic enrgy
decreases while the potential energy increases. When it goes down again the
kinetic enrgy increases again while the potential energy decreases </span>
Explanation:
It is given that,
Frequency of vibration, f = 215 Hz
Amplitude, A = 0.832 mm
(a) Let T is the period of this motion. It is given by the following relation as :



(b) Speed of sound in air, v = 343 m/s
It can be given by :




Hence, this is the required solution.