Explanation:
the object will begin to move 
 
        
                    
             
        
        
        
Answer : The energy of one photon of hydrogen atom is, 
Explanation :
First we have to calculate the wavelength of hydrogen atom.
Using Rydberg's Equation:

Where,
 = Wavelength of radiation
 = Wavelength of radiation
 = Rydberg's Constant  = 10973731.6 m⁻¹
 = Rydberg's Constant  = 10973731.6 m⁻¹
 = Higher energy level = 3
 = Higher energy level = 3
 = Lower energy level = 2
= Lower energy level = 2
Putting the values, in above equation, we get:


Now we have to calculate the energy.

where,
h = Planck's constant = 
c = speed of light = 
 = wavelength =
 = wavelength = 
Putting the values, in this formula, we get:


Therefore, the energy of one photon of hydrogen atom is, 
 
        
             
        
        
        
To answer the problem we would be using this formula which isE = hc/L where E is the energy, h is Planck's constant, c is the speed of light and L is the wavelength 
L = hc/E = 4.136×10−15 eV·s (2.998x10^8 m/s)/10^4 eV 
= 1.240x10^-10 m 
= 1.240x10^-1 nm
        
                    
             
        
        
        
Answer:
At the end points of motion (either side) the velocity must be zero because the velocity is changing from - to + (it can't turn around around without passing thru zero,
The velocity will then increase to the midpoint of the motion.
m g h = 1/2 m v^2    where h is the vertical distance thru which the pendulum travels