2m/s because the hockey puck is traveling at a constant speed ( acceleration is 0 ). Unless something acts on the hockey puck it will travel 2 m/s forever.
Answer:

Explanation:
h = Planck's constant = 
c = Speed of light = 
E = Energy = 
Wavelength ejected is given by

The maximum wavelength in angstroms of the radiation that will eject electrons from the metal is 
Answer:
36g
Explanation:
Given parameters:
Number of moles of H₂O = 2moles
Unknown:
Mass of H₂O = ?
Solution:
To solve this problem, use the expression below:
Mass of H₂O = number of moles x molar mass
Molar mass of H₂O = 2(1) + 16 = 18g/mol
Mass of H₂O = 2 x 18 = 36g