Answer: 2.67 m/s
Explanation:
Given
Mass of block A is 
mass of block B is 
The initial velocity of block A 
the initial velocity of block B is 
After collision velocity of block A is 
Conserving momentum

The momentum of block A after the collision is 
Therefore, there is no change in sign.
It describes the relationship between force and acceleration
Given:
The force of attraction is F = 48.1 N
The separation between the charges is

Also, the magnitude of charge q1 = q2 = q.
To find the magnitude of charge.
Explanation:
The magnitude of charge can be calculated by the formula

Here, k is the Coulomb's constant whose value is

On substituting the values, the magnitude of charge will be

Thus, the magnitude of each charge is 9.91 x 10^(-4) micro Coulombs.
The answer would be a radio wave
The element is iridium and it has 77 electrons