Given data
*The given 4th harmonic frequency is 31.5 Hz
The fundamental frequency is calculated as

Hence, the fundamental frequency is 7.875 Hz
Ptolemy life is probably my most recommenced
I think as a mold. when the Flood came in Genesis, i believe that when the fish were washed away, the kinda made a mold in a rock.
Answer:
(a) You can tell that have the same strength because they have attracted the same amount of paper clips.
(b) Iron is used in electromagnets because steel retained magnetic properties after the power was turned off, but in the iron, the paper clips dropped off right away.
The only vertical forces are weight and normal force, and they balance since the surface is horizontal. The horizontal forces are the applied force (uppercase F) in the direction the block slides and the frictional force (lowercase f) in the opposite direction.
Apply Newton's 2nd Law in the horizontal direction:
ΣF = ma
F - f = ma
where f = µmg
F - µmg = ma
F = m(a +µg)
F = (20 kg)(1.4 m/s² + 0.28(9.8 m/s²)
F = 83 N