To develop this problem it is necessary to apply the concept of Frequency based on speed and wavelength.
According to the definition the frequency can be expressed as

Where,
v = Velocity
Wavelength
Our value are given by,
v = 345m/s

Replacing


Therefore the frequency of the tuning fork is 547.61Hz
What is that?? Please tell us
Answer:
C. crust, mantle, core
Explanation:
density increases as you travel from the crust to the inner core
the crust is on top
next is the mantle
and then the core
Answer: C. 12.6
Explanation: 2*pi*1.8= 11.304
11.304/0.9= 12.56
KE=1/2 mv²
= 1/2 × 70 × (6)²
= 1260