<u>Answer</u>
3.44 m/s
<u>Explanation</u>
The motion apply the equations of Newton's law of motion. The ball is acceleration is -9.8 m/s² (acceleration due to gravity. It is negative because the ball is going against gravity, so it is decelerating).
The first equation of Newton's law of motion is;
V = U + at
Where V is the final velocity, U is the initial velocity, a is acceleration and t the time taken.
V = 25 + (-9.8 × 2.2)
= 25 - 21.56
= 3.44 m/s
Answer:
v (minimum speed) = 2.90 m/sec.

Maximum value of speed will occur at lowest point of vertical circle.
Explanation:
a) What minimum speed is necessary so that there is no tension in the string at the top of the circle but the rock stays in the same circular path?
Using the force balance expression at the top of the circle,
Gravitational Force + Tension force = Centrifugal force

Given that : T = 0
R = length of string = 0.86 m
mass of the spinning rock = 0.75 kg


v (minimum speed) = 2.90 m/sec.
b) what is the maximum speed the rock can have so that the string does not break?
Here the force balance at bottom of circle is represented by the illustration:

Given that:
maximum tension T = 45 N
maximum speed v = ??
mass m = 0.75 kg
∴

c)
At what point in the vertical circle does this maximum value occur?
Maximum value of speed will occur at lowest point of vertical circle.
This is so because at the lowest point; the tension in string will be maximum.
F(g)= Gm1m2/ r^2
If mass is increased, so will the force of gravity because it is in direct relationship with the gravitational force, but if distance is increased, the force of gravity will decrease because it is indirectly related ( since it is on the bottom of the equation)
Answer:
New moment of inertia will be
Explanation:
It is given initially angular velocity 
Moment of inertia 
Angular momentum is equal to 
Now angular velocity is decreases to 
As we know that angular momentum is conserved
So 

So new moment of inertia will be 
Answer:
C.
would adapt if the dress were held completely still
Explanation: