Answer:
6.21 m/s
Explanation:
Using work energy equation then

where d is displacement from initial to final position, v is velocity and subscripts a and b are position A and B respectively, m is mass of collar, g is acceleration due to gravity
Substituting 1 Kg for m, 0.4m for h,
as 0, 9.81 for g then

Answer:
Explanation:
according to third equation of motion
2as=vf²-vi²
vf²=2as+vi²
vf=√2as+vi²
vf=√2as+vi
vf=√2*2*4+3
vf=√16+3
vf=4+3=7
so final velocity is 7 m/s
Answer:

Explanation:
Knowing that the formula for average velocity is:

Being said that, we know that the person's displacement is zero because it returns to its starting point

That means 
