Complete Question
The complete question is is shown on the first uploaded
Answer:
The elastic potential energy at point B is
The kinetic energy at point D is 
Explanation:
Looking at the given point we can observe that mechanically energy(i.e potential and kinetic energy ) is conserved and it value is 
So at point B


KE at point B is 50J
So 
Now at point D

at point D is 25J
So 
Answer:
26.67 m/s
Explanation:
From the law of conservation of linear momentum, the initial sum of momentum equals the final sum.
p=mv where p is momentum, m is the mass of object and v is the speed of the object
Initial momentum
The initial momentum will be that of basketball and volleyball, Since basketball is initially at rest, its initial velocity is zero

Final momentum

Because they have special tool's that help them find out
The ball with greater mass has more density
It’s good how about you brother and sister