Answer:
it's C and D... do you understand?
Answer:

Explanation:
Given that
Radius =r
Electric filed =E
Q=Charge on the ring
The electric filed at distance x given as

For maximum condition



For maximum condition




At
the electric field will be maximum.
here we will use the concept of Newton's III law
as per Newton's III law the impulse given to the ball is same as the impulse lost by the bat
So here we will say
impulse gain by the ball = impulse lost by the bat

given that


For ball the change in speed will be

now from above equation


so speed of bat will decrease by 6.72 mph
Answer:
B) (-2.0 m, 0.0 m)
Explanation:
Given:
Mass of particle 1 is, 
Mass of particle 2 is, 
Position of center of mass is, 
Position of particle 1 is, 
Position of particle 2 is, 
We know that, the x-coordinate of center of mass of two particles is given as:

Plug in the values given.

We know that, the y-coordinate of center of mass of two particles is given as:

Plug in the values given.

Therefore, the position of particle 2 of mass 3.0 kg is (-2.0 m, 0.0 m).
So, option (B) is correct.