Wavelength = (wave speed) / (frequency)
= (1,450 m/s) / (230 / sec)
= 6.30 meters (rounded)
Hope this helped friend! :)
Answer:
(a). The first wavelength is 401.0 nm.
(b). The metal's work function is 2.55 eV.
Explanation:
Given that,
Maximum kinetic energy = 0.65 eV
Second wavelength 
(a). We need to calculate the wavelength
Using equation of work function for first wavelength
.....(I)
For second wavelength,

Put the value of second wavelength
....(II)
By subtraction equation (I) from (II)





(b). We need to calculate the work function
Using formula of work function

Put the value into the formula


Hence, (a). The first wavelength is 401.0 nm.
(b). The metal's work function is 2.55 eV.
Answer:
The total momentum of the system before the collision is 5.334 kg-m/s towards left.
Explanation:
Given that,
Mass of the block A, 
Speed of block A, 
Mass of the block B, 
Mass of block B, 
Let p is the total momentum of the system before the collision. It is given by :

So, the total momentum of the system before the collision is 5.334 kg-m/s towards left. Hence, this is the required solution.
-- Top picture:
'a' and 'b' have the same magnitude, and both are positively charged.
-- Bottom picture:
The charge on the particle is negative.