Answer:
The middle and end of the string respectively
Explanation:
Rarefaction means region of maximum displacement and compression means region of minimum displacement, hence.
We expect a maximum displacement at the middle of the string because it is said to vibrate greatest at this point and conversely vibrate least at the end point which is the region of compression.
Answer:
Acceleration of the object will be 
Explanation:
We have given mass of the object m = 9 kg
spring constant k = 95 N/m
Spring is stretched by 10 cm
So x = 10 cm = 0.1 m
We know that force is given by 
From newton's law we also know that force is given by
F = ma , here m is mass and a is acceleration
So 
The acceleration of the particle as a function of time t is

The velocity of the particle at time t is the integral of the acceleration:

where the constant C can be found by requiring that the velocity at time t=0 is v=3:

and we find

so the velocity is

The position of the particle at time t is the integral of the velocity:

where D can be found by requiring that the initial position at time t=0 is zero:
x(0)=0
from which we find D=0, so
To solve the problem, now we just have to substitute t=5 into x(t) and v(t) to find the position and the velocity of the particle at t=5.
The position is:

and the velocity is: