Answer:
1) Hence, the period is 0.33 s.
2) The amplitude is 10 cm.
Explanation:
1) The period is given by:

Where:
f: is the frequency = 3 bob up and down each second = 3 s⁻¹ = 3 Hz 
 
 
Hence, the period is 0.33 s.
2) The amplitude is the distance between the equilibrium position and the maximum position traveled by the spring. Since the spring is moving up and down over a distance of 20 cm, then the amplitude is:           
 
   
Therefore, the amplitude is 10 cm.          
I hope it helps you!                    
 
        
             
        
        
        
First we find the energy level with the following formula, where a is the energy level, n1 is the final energy level, n2 is the starting energy level and r is Rydberg's constant in Joules

We insert the values


The wavelength is found with this formula, where h is Planck's constant and c is the speed of light

Finally we insert the values

Which is the same as 93.8 nm
 
        
        
        
Answer: C Heat Transfer, E Addition of Volatiles and A Decompression
Explanation:
- Decompression melting takes place within Earth when a body of rock is held at approximately the same temperature but the pressure is reduced. 
 
        
             
        
        
        
Here’s my work to your question. I used Newton’s Second Law and a kinematics equation to arrive at the answer.