(a) 
The frequency of a wave is given by:

where
v is the wave's speed
is the wavelength
For the red laser light in this problem, we have
(speed of light)

Substituting,

(b) 427.6 nm
The wavelength of the wave in the glass is given by

where
is the original wavelength of the wave in air
n = 1.48 is the refractive index of glass
Substituting into the formula,

(c) 
The speed of the wave in the glass is given by

where
is the original speed of the wave in air
n = 1.48 is the refractive index of glass
Substituting into the formula,

Choice-'b' says the formula for kinetic energy in words.
KE = (1/2) · (M) · (S²)
Answer:
Animals are classifield as two main groups in the animal kingdom : Vertebrates and invertebrates .
Explanation:
keep it up....
Answer:
I think that the answer might be d
Answer:
magnitude of force on charge 2Q = 
Direction of force on charge = 61 ⁰
Explanation:
The magnitude on the force on the charge can be evaluated by finding the net force acting on the charge 2Q i.e x-component of the net force and the y-component of the net force
║F║ =
= after considering the forces coming from Q, 3Q and 4Q AND APPLYING COULOMBS LAW
magnitude of force acting on 2Q = 
The direction of the force on charge 2Q is calculated as
tan ∅ =
= 1.8284
therefore ∅ =
1.8284
= 61⁰