The correct answer is Electromagnetic spectrum, A,B and D are components of electromagnetic spectrum.
Answer and Explanation:
Let:

The equation representing a simple harmonic motion, where:

As you may know the derivative of the position is the velocity and the derivative of the velocity is the acceleration. So we can get the velocity and the acceleration by deriving the position:

Also, you may know these fundamental formulas:

Now, using the previous information and the data provided by the problem, let's solve the questions:
(a)

(b)

(c)

(d)
We can extract the phase of the motion, the angular frequency and the amplitude from the equation provided by the problem:

(e)

(f)

Answer:
39.2m/s
Explanation:
The potential energy the book has right before it falls is equal to the kinetic energy in falling.
PE = KE
mgh = (1/2)mv
2gh=v
v=(2)(9.81)(2)
v=39.24m/s
Answer: 
Explanation:
Given
Length of plank is 1.6 m
Force
is applied on the left side of plank
Force
is applied 43 cm from the left end O.
Mass of the plank is 
for equilibrium
Net torque must be zero. Taking torque about left side of the plank

Net vertical force must be zero on the plank

Refraction is the bending of light<span> </span>