football hemets have pads that are filled with air and thick foam so when they are hit the foam asorbs the hit and the air keeps the hard outer shell of the helmet from hiting the players head
 
        
                    
             
        
        
        
Answer:
 #_photon = 5 10²⁰ photons / s
Explanation:
For this exercise let's calculate the energy of a single quantum of energy, use Planck's law
          E = h f
          c= λ f
          E = h c / λ
           λ= 1000 nm (1 m / 109 nm) = 1000 10⁻⁹ m
Let's calculate
           E₀ = 6.6310⁻³⁴ 3 10⁸/1000 10⁻⁹
           E₀ = 19.89 10⁻²⁰ J
This is the energy emitted by a photon let's use a proportions rule to find the number emitted in P = 100 w
                 #_photon = P / E₀
                #_photon = 100 / 19.89 10⁻²⁰
               #_photon = 5 10²⁰ photons / s
 
        
             
        
        
        
A.
if you have seen a newton's cradle this will make sense.
in order for both of them to travel at the same speed, the balls need to have the same mass and the speed to begin with tocontinue to travel at the same speed because mass can affect the impact of the force on the balls by each other, causing each ball to have different speeds.
        
                    
             
        
        
        
Velocity is speed with direction. So, if velocity varies directly with speed, that statement would be true. A constant velocity would resort in a constant speed. They are connected and are dependant on each other.
I hope this helps!
~kaikers
        
             
        
        
        
Force of gravity = Mass x Gravitational force
Fg=mg
Fg = (5.7)(9.8)
Fg= 55.86 N