Answer:
a.Attractive

Explanation:
When it comes to charges, the charges which are alike repel each other and the charges which are different will attract each other.
Here, there is a proton and electron which are different particles hence, they will attract each other.
= Charge of electron and proton = 
r = Distance between them = 997 nm
k = Coulomb constant = 
Force is given by

The force of attraction between the particles will be 
Answer:
The answer is B: to Amplify the sound
Answer:
I believe the answer is C
Explanation:
Force = (mass) x (acceleration) (Newton's second law of motion)
Divide both sides of the equation by 'acceleration', and you have
Mass = (force) / (acceleration)
Mass = 17 newtons / 3.75 meters per second-sqrd = 4.533 kilograms (rounded)