Answer:
0.82 m
Explanation:
The ball is in free fall - uniform accelerated motion with constant acceleration downward, (acceleration of gravity). So we can use the following suvat equation to solve the problem:
where
v is the final velocity
u = 4 m/s is the initial velocity
a is the acceleration
s is the displacement
At the maximum displacement, v = 0 (the velocity becomes zero). Substituting and solving for s, we find:
To develop this problem it is necessary to apply the concepts related to Gravitational Potential Energy.
Gravitational potential energy can be defined as
As M=m, then
Where,
m = Mass
G =Gravitational Universal Constant
R = Distance /Radius
PART A) As half its initial value is u'=2u, then
Therefore replacing we have that,
Re-arrange to find v,
Therefore the velocity when the separation has decreased to one-half its initial value is 816m/s
PART B) With a final separation distance of 2r, we have that
Therefore
Therefore the velocity when they are about to collide is