Complete Question
A spherical wave with a wavelength of 2.0 mm is emitted from the origin. At one instant of time, the phase at r_1 = 4.0 mm is π rad. At that instant, what is the phase at r_2 = 3.5 mm ? Express your answer to two significant figures and include the appropriate units.
Answer:
The phase at the second point is 
Explanation:
From the question we are told that
The wavelength of the spherical wave is 
The first radius is 
The phase at that instant is 
The second radius is 
Generally the phase difference is mathematically represented as

this can also be expressed as

So we have that

substituting values



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
Answer:
Catastrophic theories
Explanation:
The theory of catastrophe is a collection of methods used to analyze and describe the ways in which a system can experience sudden significant behavioral changes when one or more of the variables that govern it are continuously modified.
Georges Louis de Buffon suggested in 1745 the first destructive theory — that a comet pulled material from the Sun to form the planets.
Therefore the answer is -
Catastrophic theories
Answer: Your using your skeletal muscle
Explanation: